RARE result

After the event it went to +4.43% at its lowest, and later to +17.39% at its highest, against the close price before FDA decision.

The news wasPositive

Measured fromChart

The FDA approved UX111 as FAYUVI on 17 September 2026, two days before its target date and as a standard full approval rather than the accelerated approval the application sought. It is the first treatment ever approved for Sanfilippo syndrome type A, it cleared the manufacturing objection that caused the 2025 rejection, and it came with a priority review voucher. The stock rose 12.58% on the day.

What else moved the price

About a third of the day was not this decision. The stock opened 17 September at $13.22 and had already climbed to $13.50 before the tape broke at 18:28 UTC, a gain of 4.81% on no company news, on a day the biotechnology ETF XBI closed 2.64% higher and SPY 1.13% higher. The approval itself is the move from $13.50 to the $14.50 close, 7.41%. Nothing else lands in the window: the card called the day clear and it was, with the Federal Reserve decision the day before and the monthly options expiration the day after, both outside it. Worth separating from the result is what has happened since. The stock is at $16.04 as this is written on 22 September, 12.09% above the signal price and well beyond anything the approval session produced, which is a repricing of the two priority review vouchers and the launch rather than a reaction to the decision.

What we said	What happened	Result
The FDA decides on UX111, also called rebisufligene etisparvovec, by the 19 September 2026 target date, with 95% confidence that it acts by or close to that date and 72% confidence in approval under the accelerated pathway, possibly with post-marketing requirements.	Approved, two days early and on a better pathway than the card asked for. The FDA granted standard full approval of FAYUVI on 17 September 2026, not accelerated approval, on a pivotal trial with follow-up running to nearly eight years. There is no confirmatory trial requirement, only monitoring for liver enzymes, platelets, thrombotic microangiopathy and malignancy.	Correct
Expected direction positive, on the reasoning that approval would restore part of the pipeline value lost when GTX-102 failed.	The stock rose 12.58% on the day, from the $12.88 close on 16 September to $14.50, and traded as high as $15.12 after the bell.	Correct
Stock-reaction confidence 67%, held back because approval could still produce a smaller sell-the-news move if investors focus on cash burn and commercialization risk.	Neither extreme arrived and the caution was the right shape. The day paid 12.58% from the pre-event close, but only 1.33% measured from the card's own signal price of $14.31, because the stock had drifted down to $12.88 in the week between publication and the decision.	Correct
The target date is Saturday 19 September, so the main reaction should occur on Monday 21 September, unless the FDA or company announces the decision before the close on Friday.	The escape clause is what fired. The decision landed on Thursday 17 September, inside the regular session, and Monday 21 September added only 0.97%. A reader who waited for Monday missed all of it.	Partly correct
Avoid short-dated options because the nearest standard expiration, 18 September 2026, falls before the Saturday PDUFA date.	Backwards, and this is the most expensive line on the card. The approval came on 17 September, one day before that expiration, so the contracts the card told readers to avoid are the ones that covered the event.	Incorrect
Action Watch. A small starter position only, with an add if approval produces a high-volume close above $16.10.	The starter half was right and the add never triggered. The best print of the whole move was $15.12 after hours on 17 September, the best regular-session high was $15.07 the next day, and the best close since is $14.65 on 21 September.	Correct
Expected move +12% to +25%, taking the price toward $16.03 to $17.89, larger and more positive than the historical average because the stock is oversold near its 52-week low.	Right about the size of the day and wrong about the level. The 12.58% gain from the pre-event close sits at the bottom of the range, but the range was drawn from the card's $14.31, and the stock fell almost 10% before the event, so $16.03 was never reached. From the signal price the best extended print was 5.66% and the close was 1.33%.	Correct on size, wrong on level
Historical average move -5.8% across two examples, the 2025 Complete Response Letter and the GENGLYCOS approval, both of which fell. The card overrode it and called for a rise.	The override was correct. Both earlier examples fell and this one rose 12.58%, so the two-example average was the wrong guide and the card was right to say so in advance.	Correct
Options-implied move roughly plus or minus 9.4% from the $15 strikes for the 18 September expiration, flagged as not fully covering a weekend decision.	The size was beaten and the caveat was wrong. The decision landed inside that expiration and the day moved 12.58%, above the 9.4% the options were paying for.	Underestimated
Impact strength high, on a binary decision for a late-stage gene therapy at a company whose market value had fallen to about $1.46 billion.	Confirmed by the tape. The regular session traded 11.12 million shares against a trailing average near 2.28 million, about 4.9 times normal, and the single 18:28 UTC minute traded 633,474 shares against 14,272 the minute before.	Correct
Estimated duration 1 to 3 trading days for the first reaction, with a rejection creating a sharper fall and approval capable of supporting a longer repricing.	The move held rather than faded. The stock closed at $14.50, then $14.51, then $14.65 across the three sessions after the approval, and none of the gain was given back.	Correct
Positive scenario: the FDA grants accelerated approval with a workable label, for a reaction of +12% to +25%. Neutral scenario: restrictive wording or a slow launch timetable, for 0% to +8%. Negative and severe negative scenarios: a delay at -5% to -12%, or a second Complete Response Letter at -20% to -35%.	The positive scenario occurred, with a better approval and a narrower label than it described. Full approval rather than accelerated, but the indication is limited to the neurologic manifestations of MPS IIIA in pediatric patients with preserved neurodevelopmental function, and the label carries hepatotoxicity, thrombocytopenia and malignancy warnings. Neither downside scenario came close.	Correct scenario
The strongest positive result is approval without new manufacturing restrictions, combined with a launch timetable and manageable post-marketing requirements, and approval alone may not be enough for a sustained rally if the label is narrow or capacity limits the launch.	Every condition was met and the qualifier is what explains where the move stopped. The label names the Bedford facility and Andelyn Biosciences, product ships to Qualified Treatment Centers within 30 to 60 days, and the requirements are monitoring rather than a new trial. The list price is about $3.95 million per patient into a very small population, and the rally stopped at $15.12.	Correct
RGNX, SRPT and BMRN could see smaller sentiment moves as read-through trades rather than direct economic exposures.	They moved, but with their sector rather than with this approval. On 17 September RGNX rose 2.94%, SRPT rose 4.61% and BMRN rose 0.54%, against the biotechnology ETF XBI at 2.64% and the S&P 500 ETF SPY at 1.13%. Only SRPT beat its index, and BMRN lagged it.	Partly correct
What the market may be missing: the August 2026 GENGLYCOS approval followed an inspection of the Bedford facility and showed the company can get a self-manufactured gene therapy approved, which lowers the chance that the manufacturing concern behind the 2025 rejection is company-wide.	This is the best call on the card and it is the reason the decision went the way it did. The approval names Bedford as a manufacturing site, so the chemistry, manufacturing and controls objection that produced the Complete Response Letter was cleared. What the card missed is the other half of the ledger: approval came with a rare pediatric disease priority review voucher, the company's second, and vouchers sold in 2026 for $180 million to $205 million, so the pair is worth roughly a quarter of the market value the card was working from. Cantor Fitzgerald raised its target to $39 from $33 the next day and now assumes a voucher sale.	Correct, and incomplete
Technical bias bearish. A close below $13.80 would confirm the base failed and expose $12 to $13. A high-volume close above $16.10 would invalidate the bearish bias and suggest a rebound toward $20.	Both halves were right and the downside half fired first. The stock closed at $13.61 on 14 September, below the level, and traded to $12.73 on 16 September, inside the zone the card named. The upside trigger has still not fired: the best close since the approval is $14.65.	Correct
Support is $13.80 to $14.30. First resistance is $15.20 to $15.30, second resistance $16.00 to $16.10.	The support failed and the first resistance held to nine cents. The stock broke $13.80 on 14 September and bottomed at $12.73, then the entire approval rally stopped at $15.12 after hours and $15.07 in regular trade, just under the $15.20 the card had marked.	Partly correct

Price Table	Price (USD)	Change from signal	Change from lowest (regular session)	Change from close before FDA decision
After signal
Price at analysis (Pre-market)10 Sept 2026, 08:02	14.31	—	+12.41%
Sat 12, Sun 13 - no trading
Lowest price (Regular session)16 Sept 2026, 19:25	12.73	−11.04%	—
Highest price (Regular session)11 Sept 2026, 13:34	14.70	+2.73%	+15.48%
Sat 12, Sun 13 - no trading
Close price before FDA decisionWed 16 Sept 2026, 20:00, close	12.88	−9.99%	+1.18%
After FDA decision (17 Sep 2026, 18:28 UTC)
Price after FDA decision (Regular session)17 Sept 2026, 18:28	13.50	−5.66%	+6.05%	+4.81%
Lowest price (Regular session)17 Sept 2026, 18:34	13.45	−6.01%	+5.66%	+4.43%
Highest price (Regular session)17 Sept 2026, 19:59	14.58	+1.89%	+14.53%	+13.20%
Highest price (After-hours)17 Sept 2026, 20:23	15.12	+5.66%	+18.77%	+17.39%
Close price after FDA decisionThu 17 Sept 2026, 20:00, close	14.50	+1.33%	+13.90%	+12.58%
Sat 19, Sun 20 - no trading
Current price (Regular session)22 Sept 2026, 16:44	16.04	+12.09%	+26.00%	+24.53%

Recorded after the event and not edited since. Past moves are not a forecast of future ones.

RAREUltragenyx Pharmaceutical Inc.

Positive

FDA decision on UX111 could restore part of Ultragenyx's lost pipeline value

Event passedSat, 19 Sept 2026

FDA and Clinical

StockThe company this write-up is about, with its ticker symbol.: RARE, Ultragenyx Pharmaceutical Inc.
PriceWhere the shares traded when this write-up was made, and the exact minute that price was struck.: $14.31, 08:02 10/September/2026
Event Date And TimeWhen the event is expected. Shown in your own time zone, or in UTC if you switch the clock at the top of the page. If the exact hour is not confirmed, you only see the date.: 19/September/2026, time not confirmed
What else lands that dayOther news and events on the same day that could push the price around, and whether they help this trade, bury it, or work against it.: ClearThe PDUFA date is Saturday with no regular US session, so the first clean reaction is likely Monday unless the FDA acts earlier.
Expected Stock ReactionWhich way we expect the share price to go after the event. Positive means it rises, Negative means it falls, Mixed means it could go either way.: Positive
Technical biasWhat the chart alone suggests, ignoring the news. Rated Bullish, Neutral or Bearish.: Bearish
ActionWhat we suggest you do before the event. Buy, Watch or Avoid.: Watch
Catalyst confidenceHow sure we are that the event happens as described. Scored out of 100. Higher means more sure.: 72/100
Stock-reaction confidenceHow sure we are that the stock reacts the way we expect. Scored out of 100. Higher means more sure.: 67/100

Expected price move and durationHow far the share price may move because of this event, and how long that move may last.

Historical average moveHow much this stock moved on average after similar events in the past.: -5.8%
Our expected moveOur own estimate of the move, after weighing the market's estimate, the past moves and the situation now.: +12% to +25%
ImpactHow big we think that move is for this stock. Rated Low, Medium or High.: High
Estimated durationHow long the move is likely to last, such as intraday, a few trading days, or several weeks.: 1-3 trading days

Priced-in levelHow much of this news the share price already reflects. Rated Low, Medium or High. The higher it is, the less room the price has left to move.: Low
Risk levelHow much can go wrong with this idea if the event surprises. Rated Low, Medium or High.: High
Other affected StocksOther companies that could move on the same news, such as suppliers and competitors.: RGNX , SRPT , BMRN

Company overviewHow good the company itself is, setting this event aside. Useful if you plan to hold the shares rather than trade the news.

Company qualityHow solid the business is overall. Rated Strong, Average or Weak.: Average
GrowthHow fast the company is growing its sales and profit. Rated Low, Medium or High.: Medium
Financial healthCash, debt, cash flow and profit margins, and whether the company keeps issuing new shares. Rated Strong, Average or Weak.: Weak
ValuationWhat you pay today for what the company earns, next to its rivals and its own past. Rated Cheap, Fair or Expensive.: Fair
RiskHow much could go wrong with the business over years. Rated Low, Medium or High. This is not Risk level above, which is about this one event.: High
Overall outlookOur long-term view of the company. Positive, Neutral or Negative. This is not Expected Stock Reaction, which covers one event.: Neutral
Best suited forThe kind of investor this stock fits, such as someone holding for years or someone who wants income.: Speculative biotechnology investors

Upcoming catalystThe event that could move the share price.

FDA decision on UX111, also called rebisufligene etisparvovec, scheduled for 19 September 2026. The application seeks accelerated approval for Sanfilippo syndrome type A. The target date is confirmed, but the FDA has not published a decision time.

Main stock affectedThe company the event affects most directly.

Ultragenyx Pharmaceutical Inc., Nasdaq ticker RARE.

Current priceWhere the shares traded when this write-up was made, and when that was.

$14.31 as of 10 Sept 2026, 08:02 UTC.

Expected stock reactionWhich way we expect the share price to go after the event. Positive means it rises, Negative means it falls, Mixed means it could go either way.

Positive. Approval could restore part of the pipeline value lost after the recent GTX-102 trial failure.

Action before the eventWhat we suggest you do before the event. Buy, Watch or Avoid.

Watch. Do not take a full position before a binary FDA decision. My preferred trade is to buy a small starter position only, then add if approval produces a high-volume close above $16.10. Avoid short-dated options because the nearest standard expiration falls before the Saturday PDUFA date.

Why the stock is affectedThe link between the event and this company.

UX111 is a one-time gene therapy for a serious childhood disease with no approved treatment addressing its underlying cause. The FDA previously rejected the application because of manufacturing and quality-control observations, not because it rejected the clinical efficacy data. Approval would validate the repaired manufacturing package and add another potential commercial gene therapy. A second rejection would question Ultragenyx's manufacturing controls and remove more pipeline value after the GTX-102 failure.

Catalyst confidenceHow sure we are that the event happens as described. Scored out of 100. Higher means more sure.

72%. Approval is my base case. I estimate 95% confidence that the FDA acts by or close to the target date and 72% confidence in approval. The earlier rejection focused on chemistry, manufacturing and controls. The resubmission includes longer follow-up, and Ultragenyx recently passed the regulatory process for another gene therapy.

Stock-reaction confidenceHow sure we are that the stock reacts the way we expect. Scored out of 100. Higher means more sure.

67%. The stock is deeply oversold and has already lost 44% in one session following the unrelated GTX-102 failure. That creates rebound potential, but approval could still produce a smaller sell-the-news move if investors focus on cash burn and commercialization risk.

When the market will reactThe moment the price is likely to move, such as at the announcement or at the next market open.

The target date is Saturday, 19 September 2026. The main reaction should occur on Monday, 21 September 2026, unless the FDA or company announces the decision before the close on Friday. Expect the largest move in the first hour, followed by price discovery over one to three trading days.

Effect on the businessWhat the event changes for the company itself, such as its sales, costs or profit.

Approval would create a second newly launched gene therapy alongside GENGLYCOS and expand Ultragenyx's commercial portfolio beyond Crysvita and Dojolvi. Near-term revenue would start slowly because treatment centres, reimbursement and patient identification take time. The larger immediate effect would be higher pipeline value and improved confidence in the company's gene-therapy manufacturing platform. A rejection would delay revenue, create additional regulatory costs and weaken confidence in the company's Bedford manufacturing operation. It would also be damaging because UX111 already received one Complete Response Letter.

Market expectations and forecastWhat investors already expect from this event, and the numbers being forecast.

The market appears to expect a meaningful chance of approval, but confidence is not high. The previous Complete Response Letter identified manufacturing observations that the company described as addressable. The clinical package included up to eight years of follow-up, durable biomarker reductions and developmental stabilization or improvement compared with natural history. My forecast is approval under the accelerated approval pathway, possibly with post-marketing requirements. I estimate a 72% approval probability, an 18% probability of another delay or additional information request, and a 10% probability of a new Complete Response Letter.

How much is already priced inHow much of the expected outcome the share price already reflects before the event happens.

Low. RARE fell 44.0% on 3 September 2026 after GTX-102 failed its Phase 3 Aspire trial. It then closed at $14.31 on 9 September, only 3.6% above the $13.81 post-crash low. The selloff removed substantial pipeline value and overshadowed the UX111 decision. Approval is known as a possibility, but the current $1.46 billion market value is close to two times 2025 revenue. The price still reflects continued losses, financing risk and distrust following several pipeline setbacks.

What else lands that dayOther news and events on the same day that could push the price around, and whether they help this trade, bury it, or work against it.

The PDUFA date falls on a Saturday, when US equity markets are closed. No major US economic release is scheduled for that Saturday. Friday, 18 September, includes industrial production and monthly options expiration, which can distort the predecision price and volume. The practical takeaway is simple. Friday's closing move may reflect options positioning rather than leaked information about the FDA decision. If the news arrives during the weekend, Monday's opening price will be the first reliable market response.

Expected price move and durationHow far the share price may move because of this event, and how long that move may last.

Options-Implied Move Reliable post-event options-implied data is unavailable. The 18 September 2026 standard options expiration occurs before the Saturday PDUFA date. The $15 call and put for that expiration were pricing about $1.40 combined from a $14.88 reference price, roughly ±9.4%, but this does not fully cover a weekend decision. The ± sign measures size, not direction. Historical Event Analysis 11 July 2025, UX111 Complete Response Letter. The FDA cited manufacturing observations. Shares were indicated about 8.0% lower in the next premarket session. Reaction window: first tradable session. 19 August 2026, GENGLYCOS accelerated approval. RARE initially rose outside regular hours, then closed the next regular session down 3.51%, from $26.24 to $25.32. Reaction window: one trading day. Historical Average Move -5.8% across two limited examples. Calculation: negative 8.0% plus negative 3.51%, divided by two, equals negative 5.76%, rounded to -5.8%. Both examples fell, although one was a rejection and one was an approval. The sample is limited and the current setup is different because RARE has already suffered a separate 44% collapse. Our Expected Move +12% to +25%. This is larger and more positive than the limited historical average because the stock is oversold, trades near its 52-week low and has already removed significant pipeline value. Approval could move the price toward $16.03 to $17.89. A close above $16.10 would also clear the first meaningful post-crash resistance area. Impact Strength High. This is a binary decision involving a late-stage gene therapy, a prior rejection and a company whose market value has fallen to about $1.46 billion. Estimated Duration 1-3 trading days for the first reaction. Approval followed by credible pricing, reimbursement and launch details could support a repricing lasting several weeks. A rejection would probably create a sharper immediate fall, followed by a slower assessment of cash needs and remaining pipeline value.

Result needed for a big moveWhat the outcome has to be for the stock to move a lot instead of a little.

The strongest positive result is full accelerated approval without new manufacturing restrictions, combined with a launch timetable and manageable post-marketing requirements. Approval alone may not be enough for a sustained rally if the label is narrow or manufacturing capacity limits the launch.

Possible outcomesThe main ways the event could turn out, with the expected stock reaction for each one.

Positive scenario: FDA grants accelerated approval with a workable label. Expected reaction: +12% to +25%, with a possible move toward $16.00 to $18.00. Neutral scenario: Approval includes restrictive wording, substantial post-marketing work or a slow launch timetable. Expected reaction: 0% to +8% after an unstable opening. Negative scenario: The FDA delays action or requests additional information. Expected reaction: -5% to -12%. Severe negative scenario: A second Complete Response Letter identifies unresolved manufacturing or new safety issues. Expected reaction: -20% to -35%.

Other affected stocksOther companies that could move on the same news, such as suppliers and competitors.

RGNX, SRPT and BMRN could see smaller sentiment moves because each has material exposure to rare-disease or gene-therapy development. These are read-through trades, not direct economic exposures.

What the market may be missingSomething we think investors have overlooked or read wrong.

The FDA's August 2026 approval of GENGLYCOS is important beyond that product. The approval followed an inspection of Ultragenyx's Bedford manufacturing facility and showed that the company can obtain approval for a self-manufactured gene therapy. This does not guarantee UX111 approval, but it lowers the chance that every manufacturing concern is company-wide. The market may also be underestimating the benefit of owning a commercial rare-disease platform. Existing 2026 revenue guidance of $730 million to $760 million excludes revenue from new launches, so RARE is not dependent on UX111 for all of its revenue.

Main risksWhat could go wrong, and what would prove this call wrong.

Overall risk level: High. The decision is binary. The FDA may find unresolved manufacturing problems, require more data or grant a narrower label than expected. Even after approval, patient identification, treatment-centre capacity, reimbursement and one-time gene-therapy pricing could limit uptake. The trade can also fail if the broad market sells off, if investors use approval as an opportunity to exit, or if the company needs additional financing sooner than expected.

Other factorsAnything else worth knowing that the sections above do not cover.

Position size matters more than entry precision. A 20% to 35% downside gap is possible on a second rejection. If you trade before the decision, keep the position small enough that this loss does not damage your portfolio. My preferred setup is a starter share position, followed by an add only after approval and a close above $16.10 on strong volume.

Trend over 6 to 12 monthsWhich way the share price has been heading over the past year, and how far it has travelled.

Bearish. RARE declined from $31.29 on 10 September 2025 to $14.31 on 9 September 2026, a 54.3% loss. The highest closing area in the 52-week period was near $39.89 in December 2025. The lowest traded price was $13.81 on 3 September 2026.

Recent price actionWhat the shares have done over the last few weeks and sessions, and on what kind of volume.

RARE fell from $26.53 on 2 September to $14.85 on 3 September, a 44.0% one-day decline after GTX-102 failed its Phase 3 study. Volume reached about 27.2 million shares, roughly 12 times normal volume. The stock recovered to $15.30 on 4 September, then fell to $14.31 by 9 September. It is only $0.50, or 3.6%, above its $13.81 low. It sits about 1.9% of the way up from the bottom of its $13.81 to $39.89 52-week range.

Market structureThe shape of the chart. Rising highs and rising lows mean an uptrend, falling ones mean a downtrend, and neither means the price is stuck in a range.

The structure is a downtrend with lower highs and lower lows. The 3 September price gap broke the previous $24 to $28 trading range. The stock is now attempting to form a new base between about $13.80 and $16.10. In simple terms, buyers have appeared near $14, while sellers have repeatedly returned above $15.

Support and resistance zonesPrice areas where buyers have stepped in before, and price areas where sellers have. They often slow the price down when it gets there again.

Support is $13.80 to $14.30. The area was tested on 3 September and again near the 9 September low. A close below $13.80 would confirm a fresh breakdown and expose the $12 to $13 area. First resistance is $15.20 to $15.30. It was tested around 4, 8 and 9 September. A close above it would show that buyers are absorbing post-crash supply. Second resistance is $16.00 to $16.10, tested on 4 September. Above that, the large price gap creates resistance near $20 and again near $25 to $26.

50-day and 200-day moving averagesThe average closing price over the last 50 days and the last 200 days. Where the price sits against them shows whether the recent trend is strong or fading.

The 50-day simple moving average is about $27.39. The 200-day simple moving average is about $25.91. Price is below both by more than 44%. A moving average is simply the average closing price over the stated number of trading days. The 50-day average remains above the 200-day average because moving averages react slowly. Both averages are likely to turn lower after the 44% gap. I cannot confirm the exact date when their arrangement last changed.

Relative strengthHow this stock has performed against the wider market and against its own sector over the same period.

RARE's verified 12-month return is -54.3%. I cannot confirm exact same-timestamp 12-month returns for the S&P 500 and biotechnology sector. The stock is clearly showing weak absolute momentum, and its 44% event-driven fall caused a major deterioration in relative performance during the last month.

Volume trendHow many shares are changing hands lately compared with normal. Heavy volume behind a move means more traders agree with it.

Recent volume is elevated. The 9 September session traded about 4.58 million shares, compared with a trailing average near 2.28 million, or roughly 2.0 times normal. The 3 September collapse traded about 27.2 million shares. Heavy volume confirmed that institutions participated in the decline.

VolatilityHow much the share price swings day to day right now, compared with how much it usually swings.

The 14-day average true range is about $2.07, equal to 14.5% of the $14.31 price. This is very high and is inflated by the 44% gap. The 9 September intraday range was $0.92, or 6.4% of the closing price. You should use a smaller position than normal. A tight stop of a few cents is unsuitable because ordinary daily movement can exceed $0.90.

Long-Term Technical ViewThe wider chart over years. The big trend, the major price levels and how much the stock swings.

The multi-year chart is bearish. RARE has fallen from much higher 2020 and 2021 levels and has repeatedly failed to sustain recoveries. The new long-term support area is $13 to $14. Major resistance is $25 to $30, followed by the $39 to $40 area.

Technical biasWhat the chart alone suggests, ignoring the news. Rated Bullish, Neutral or Bearish.

Bearish. Price is below the 50-day and 200-day averages, the chart has a major downside gap, and the stock remains close to its 52-week low. This conflicts with my positive catalyst call. I give more weight to the FDA event for the immediate trade, but the bearish chart means I require confirmation before adding.

What would invalidate this biasThe price level or chart change that would prove the technical read wrong.

A high-volume daily close above $16.10 would invalidate the immediate bearish bias and suggest a rebound toward $20. A close below $13.80 would confirm that the base failed and shift the next downside focus toward $12 to $13.

Technical data timestampWhen the chart figures above were taken. Markets keep moving, so check live charts before you trade.

9 September 2026, 20:00 UTC, reflecting the completed regular US session. Markets move after this report is written. Check live charts and current levels before placing a trade.

Stock OverviewThe basic numbers. Price, size of the company, sector, the past year of highs and lows, trading volume and the next earnings date.

RARE traded at $14.31 at 10 September 2026, 08:02 UTC. Market value was approximately $1.46 billion. Ultragenyx is in the healthcare sector and biotechnology industry. Its 52-week range was $13.81 to $39.89. Trailing average daily volume was approximately 2.28 million shares. The next earnings date is estimated for 3 November 2026 and is not confirmed.

What the company doesThe business in plain words. What it sells, who buys it, and how the money reaches the company.

Ultragenyx develops and sells treatments for rare genetic diseases. Its customers are hospitals, specialist treatment centres and healthcare systems. Revenue comes from direct product sales, royalties and profit-sharing arrangements. An easy example is Crysvita. It treats certain inherited phosphate disorders. Ultragenyx receives product revenue and royalties as patients receive ongoing treatment. Gene therapies such as GENGLYCOS and UX111 are different because they are designed as one-time treatments.

Revenue BreakdownWhere the money comes from, split by product, by part of the business and by country.

Second-quarter 2026 revenue was $214 million. Crysvita contributed $156 million, or 72.9%. Dojolvi contributed $27 million, or 12.6%. Evkeeza contributed $21 million, or 9.8%. Mepsevii contributed $10 million, or 4.7%. Crysvita is the largest dependency. A slowdown in Crysvita demand or royalties would materially reduce revenue and cash generation. I cannot confirm a complete current revenue split by country from the latest reported quarter.

Company GrowthHow sales, profit, earnings per share and spare cash have changed over the last few years.

Revenue rose from $351 million in 2021 to $363 million in 2022, $434 million in 2023, $560 million in 2024 and $673 million in 2025. The four-year compound annual growth rate was approximately 17.7%. Growth accelerated in 2023 and 2024, then slowed to 20.2% in 2025. Net losses were $454 million in 2021, $707 million in 2022, $607 million in 2023, $569 million in 2024 and $575 million in 2025. EPS was negative $6.70, negative $10.12, negative $8.25, negative $6.29 and negative $5.83 across those years. Revenue is growing, but profit has not followed because research, launch and administrative spending remain high. Annual free cash flow remained negative, approximately negative $349 million in 2021, negative $587 million in 2022, negative $506 million in 2023, negative $448 million in 2024 and negative $464 million in 2025. Revenue is the fastest-improving measure. Free cash flow is the weakest.

Earnings PerformanceThe latest results, whether they beat or missed what the market expected, and what the company says comes next.

Second-quarter 2026 revenue was $214 million and net loss was $0.90 per share. Revenue increased 28.1% from $167 million, while the loss improved from $1.17 per share one year earlier. I cannot confirm reliable consensus figures for that quarter. First-quarter 2026 revenue was $136 million and loss per share was $1.84. Fourth-quarter 2025 revenue was $207 million and loss per share was $1.29. Third-quarter 2025 revenue was approximately $160 million and loss per share was $1.81. I cannot confirm consistent consensus comparisons for these quarters. Management reaffirmed 2026 revenue guidance of $730 million to $760 million, excluding new product launches. It also expects combined research and administrative expenses to be flat to slightly lower than 2025.

Financial HealthCash, debt, cash flow and profit margins, and whether the company keeps issuing new shares. Rated Strong, Average or Weak.

Cash, cash equivalents and marketable securities were $436 million on 30 June 2026. Cash used in operations was $294 million in the first half. The company reported $1.20 billion of liabilities linked to previously sold future royalties. Treating those royalty liabilities like debt gives an adjusted net liability of about $766 million after cash. Second-quarter gross margin was 84.1%, calculated as revenue of $214 million minus $34 million cost of sales, divided by revenue. Operating margin was negative 35.0%, calculated as the $75 million operating loss divided by revenue. Gross margin narrowed from 86.2% one year earlier, while operating margin improved from negative 64.7%. Shares outstanding increased from about 96.6 million at the end of 2025 to 98.6 million by 31 July 2026, an increase of about 2.1%. Management stated that available capital should cover at least the next 12 months. The company can survive a bad year, but another capital raise or royalty financing remains possible.

ValuationWhat you pay today for what the company earns, next to its rivals and its own past. Rated Cheap, Fair or Expensive.

Trailing P/E, forward P/E and PEG are not meaningful because earnings are negative. EV-to-EBITDA is also not meaningful because EBITDA is negative. Using a $1.46 billion market value, $436 million of cash and $1.20 billion of future-royalty liabilities produces an adjusted enterprise value near $2.22 billion. Against $717 million of trailing revenue, adjusted EV-to-sales is approximately 3.1 times. Calculation: $1.46 billion plus $1.20 billion minus $0.44 billion, divided by $0.717 billion. These ratios show how much you pay today for each dollar the company earns or sells. The stock looks fair rather than clearly cheap because revenue is growing, but losses, dilution and pipeline risk are high.

ShareholdersWho owns the company. Big funds, company insiders, and whether ownership sits with only a few holders.

The March 2026 proxy listed Vanguard as the only reported holder above 5%, with 8.8%. Chief executive Emil Kakkis held 3.4%. Directors and executive officers as a group held 5.2%. Ownership is not highly concentrated in one controlling shareholder.

Insider ActivityWhether the people running the company have been buying or selling their own shares lately.

Chief financial officer Howard Horn sold 1,635 shares at $22.40 on 3 March 2026. The filing also recorded equity compensation awards. A September filing included shares acquired through the employee stock purchase plan, which is not the same as a discretionary open-market purchase. I cannot confirm a material recent open-market insider purchase. The pattern is routine selling and compensation activity rather than strong insider buying.

Dividends and BuybacksCash paid out to shareholders, whether that payment looks safe, and whether the company is buying back its own shares.

Ultragenyx pays no dividend. I cannot confirm an active share-repurchase programme. Cash is being used for research, launches and operations, which is normal for a loss-making biotechnology company.

Competitive PositionWho the company competes with, how much of the market it holds, and what it has that rivals do not.

Ultragenyx has a commercial rare-disease sales platform, several approved products and internal gene-therapy manufacturing capability. Its main strategic advantage is experience finding very small patient populations and taking specialised treatments through development, reimbursement and launch. Competitors include BioMarin, Sarepta, Regenxbio and other rare-disease developers. Its advantage is useful but not fully durable. Failed trials, manufacturing problems, competing therapies or payer resistance can quickly reduce a rare-disease product's value.

Future OutlookWhat sales and profit are expected to do next, and what management has promised.

Management expects 2026 revenue of $730 million to $760 million, growth of 8% to 13% from 2025 before revenue from new launches. It previously targeted profitability in 2027, but the GTX-102 failure removed an important future revenue source and makes that path less certain. My view is neutral. Existing product growth and GENGLYCOS support the business. Continued cash burn, the failed GTX-102 study and manufacturing risk offset that progress.

Other Upcoming Company CatalystsOther events ahead that could move the share price, such as results, launches or approvals, apart from the catalyst this report is built on.

Potential GENGLYCOS launch updates during late 2026. UX701 dose-finding data for Wilson disease expected in the fourth quarter of 2026. A specific date is not published. DTX301 Phase 3 treatment-burden data expected in the first half of 2027. A specific date is not published. The next quarterly earnings report is estimated for November 2026 but is not confirmed.

Long-Term Company RisksWhat could weaken the business over the coming years, rather than around this one event.

The largest risk is repeated clinical failure. UX143 failed important studies in 2025 and GTX-102 failed Phase 3 in September 2026. This shows that a broad pipeline does not guarantee successful products. Financial risk is also high. Ultragenyx remains unprofitable, used $294 million of operating cash in the first half of 2026 and has sold rights to future Crysvita royalties. That financing helps today but gives up part of future cash flow. Other risks include dependence on Crysvita, manufacturing complexity, one-time treatment economics, reimbursement delays and share dilution. The repeated late-stage failures worry me most for a multi-year holding.

Traderavel VerdictOur straight answer on the company after everything above, not on the trade. Quality, growth, price, risk and the long-term view.

Ultragenyx is an average-quality biotechnology business with medium growth, weak financial health and high long-term risk. Its commercial products provide real revenue and distinguish it from a development-only biotech. Revenue has grown at a strong rate, but the company has not converted that growth into profit or positive cash flow. The valuation is fair after the share-price collapse. It is not clearly cheap because pipeline failures, future-royalty liabilities and dilution reduce the value of each revenue dollar. My long-term outlook is neutral until the company shows successful launches, lower cash burn and a credible route to profitability. The stock suits speculative biotechnology investors who can accept clinical, regulatory and financing volatility. It does not suit income investors, conservative portfolios or anyone unable to tolerate sudden losses of 20% to 40%.

For information only · not financial advice.

Expected price move and durationiHow far the share price may move because of this event, and how long that move may last.

Company overviewiHow good the company itself is, setting this event aside. Useful if you plan to hold the shares rather than trade the news.

Upcoming catalystiThe event that could move the share price.

Main stock affectediThe company the event affects most directly.

Current priceiWhere the shares traded when this write-up was made, and when that was.

Expected stock reactioniWhich way we expect the share price to go after the event. Positive means it rises, Negative means it falls, Mixed means it could go either way.

Action before the eventiWhat we suggest you do before the event. Buy, Watch or Avoid.

Why the stock is affectediThe link between the event and this company.

Catalyst confidenceiHow sure we are that the event happens as described. Scored out of 100. Higher means more sure.

Stock-reaction confidenceiHow sure we are that the stock reacts the way we expect. Scored out of 100. Higher means more sure.

When the market will reactiThe moment the price is likely to move, such as at the announcement or at the next market open.

Effect on the businessiWhat the event changes for the company itself, such as its sales, costs or profit.

Market expectations and forecastiWhat investors already expect from this event, and the numbers being forecast.

How much is already priced iniHow much of the expected outcome the share price already reflects before the event happens.

What else lands that dayiOther news and events on the same day that could push the price around, and whether they help this trade, bury it, or work against it.

Expected price move and durationiHow far the share price may move because of this event, and how long that move may last.

Result needed for a big moveiWhat the outcome has to be for the stock to move a lot instead of a little.

Possible outcomesiThe main ways the event could turn out, with the expected stock reaction for each one.

Other affected stocksiOther companies that could move on the same news, such as suppliers and competitors.

What the market may be missingiSomething we think investors have overlooked or read wrong.

Main risksiWhat could go wrong, and what would prove this call wrong.

Other factorsiAnything else worth knowing that the sections above do not cover.

Trend over 6 to 12 monthsiWhich way the share price has been heading over the past year, and how far it has travelled.

Recent price actioniWhat the shares have done over the last few weeks and sessions, and on what kind of volume.

Market structureiThe shape of the chart. Rising highs and rising lows mean an uptrend, falling ones mean a downtrend, and neither means the price is stuck in a range.

Support and resistance zonesiPrice areas where buyers have stepped in before, and price areas where sellers have. They often slow the price down when it gets there again.

50-day and 200-day moving averagesiThe average closing price over the last 50 days and the last 200 days. Where the price sits against them shows whether the recent trend is strong or fading.

Relative strengthiHow this stock has performed against the wider market and against its own sector over the same period.

Volume trendiHow many shares are changing hands lately compared with normal. Heavy volume behind a move means more traders agree with it.

VolatilityiHow much the share price swings day to day right now, compared with how much it usually swings.

Long-Term Technical ViewiThe wider chart over years. The big trend, the major price levels and how much the stock swings.

Technical biasiWhat the chart alone suggests, ignoring the news. Rated Bullish, Neutral or Bearish.

What would invalidate this biasiThe price level or chart change that would prove the technical read wrong.

Technical data timestampiWhen the chart figures above were taken. Markets keep moving, so check live charts before you trade.

Stock OverviewiThe basic numbers. Price, size of the company, sector, the past year of highs and lows, trading volume and the next earnings date.

What the company doesiThe business in plain words. What it sells, who buys it, and how the money reaches the company.

Revenue BreakdowniWhere the money comes from, split by product, by part of the business and by country.

Company GrowthiHow sales, profit, earnings per share and spare cash have changed over the last few years.

Earnings PerformanceiThe latest results, whether they beat or missed what the market expected, and what the company says comes next.

Financial HealthiCash, debt, cash flow and profit margins, and whether the company keeps issuing new shares. Rated Strong, Average or Weak.

ValuationiWhat you pay today for what the company earns, next to its rivals and its own past. Rated Cheap, Fair or Expensive.

ShareholdersiWho owns the company. Big funds, company insiders, and whether ownership sits with only a few holders.

Insider ActivityiWhether the people running the company have been buying or selling their own shares lately.

Dividends and BuybacksiCash paid out to shareholders, whether that payment looks safe, and whether the company is buying back its own shares.

Competitive PositioniWho the company competes with, how much of the market it holds, and what it has that rivals do not.

Future OutlookiWhat sales and profit are expected to do next, and what management has promised.

Other Upcoming Company CatalystsiOther events ahead that could move the share price, such as results, launches or approvals, apart from the catalyst this report is built on.

Long-Term Company RisksiWhat could weaken the business over the coming years, rather than around this one event.

Traderavel VerdictiOur straight answer on the company after everything above, not on the trade. Quality, growth, price, risk and the long-term view.

Expected price move and durationHow far the share price may move because of this event, and how long that move may last.

Company overviewHow good the company itself is, setting this event aside. Useful if you plan to hold the shares rather than trade the news.

Upcoming catalystThe event that could move the share price.

Main stock affectedThe company the event affects most directly.

Current priceWhere the shares traded when this write-up was made, and when that was.

Expected stock reactionWhich way we expect the share price to go after the event. Positive means it rises, Negative means it falls, Mixed means it could go either way.

Action before the eventWhat we suggest you do before the event. Buy, Watch or Avoid.

Why the stock is affectedThe link between the event and this company.

Catalyst confidenceHow sure we are that the event happens as described. Scored out of 100. Higher means more sure.

Stock-reaction confidenceHow sure we are that the stock reacts the way we expect. Scored out of 100. Higher means more sure.

When the market will reactThe moment the price is likely to move, such as at the announcement or at the next market open.

Effect on the businessWhat the event changes for the company itself, such as its sales, costs or profit.

Market expectations and forecastWhat investors already expect from this event, and the numbers being forecast.

How much is already priced inHow much of the expected outcome the share price already reflects before the event happens.

What else lands that dayOther news and events on the same day that could push the price around, and whether they help this trade, bury it, or work against it.

Expected price move and durationHow far the share price may move because of this event, and how long that move may last.

Result needed for a big moveWhat the outcome has to be for the stock to move a lot instead of a little.

Possible outcomesThe main ways the event could turn out, with the expected stock reaction for each one.

Other affected stocksOther companies that could move on the same news, such as suppliers and competitors.

What the market may be missingSomething we think investors have overlooked or read wrong.

Main risksWhat could go wrong, and what would prove this call wrong.

Other factorsAnything else worth knowing that the sections above do not cover.

Trend over 6 to 12 monthsWhich way the share price has been heading over the past year, and how far it has travelled.

Recent price actionWhat the shares have done over the last few weeks and sessions, and on what kind of volume.

Market structureThe shape of the chart. Rising highs and rising lows mean an uptrend, falling ones mean a downtrend, and neither means the price is stuck in a range.

Support and resistance zonesPrice areas where buyers have stepped in before, and price areas where sellers have. They often slow the price down when it gets there again.

50-day and 200-day moving averagesThe average closing price over the last 50 days and the last 200 days. Where the price sits against them shows whether the recent trend is strong or fading.

Relative strengthHow this stock has performed against the wider market and against its own sector over the same period.

Volume trendHow many shares are changing hands lately compared with normal. Heavy volume behind a move means more traders agree with it.

VolatilityHow much the share price swings day to day right now, compared with how much it usually swings.

Long-Term Technical ViewThe wider chart over years. The big trend, the major price levels and how much the stock swings.

Technical biasWhat the chart alone suggests, ignoring the news. Rated Bullish, Neutral or Bearish.

What would invalidate this biasThe price level or chart change that would prove the technical read wrong.

Technical data timestampWhen the chart figures above were taken. Markets keep moving, so check live charts before you trade.

Stock OverviewThe basic numbers. Price, size of the company, sector, the past year of highs and lows, trading volume and the next earnings date.

What the company doesThe business in plain words. What it sells, who buys it, and how the money reaches the company.

Revenue BreakdownWhere the money comes from, split by product, by part of the business and by country.

Company GrowthHow sales, profit, earnings per share and spare cash have changed over the last few years.

Earnings PerformanceThe latest results, whether they beat or missed what the market expected, and what the company says comes next.

Financial HealthCash, debt, cash flow and profit margins, and whether the company keeps issuing new shares. Rated Strong, Average or Weak.

ValuationWhat you pay today for what the company earns, next to its rivals and its own past. Rated Cheap, Fair or Expensive.

ShareholdersWho owns the company. Big funds, company insiders, and whether ownership sits with only a few holders.

Insider ActivityWhether the people running the company have been buying or selling their own shares lately.

Dividends and BuybacksCash paid out to shareholders, whether that payment looks safe, and whether the company is buying back its own shares.

Competitive PositionWho the company competes with, how much of the market it holds, and what it has that rivals do not.

Future OutlookWhat sales and profit are expected to do next, and what management has promised.

Other Upcoming Company CatalystsOther events ahead that could move the share price, such as results, launches or approvals, apart from the catalyst this report is built on.

Long-Term Company RisksWhat could weaken the business over the coming years, rather than around this one event.

Traderavel VerdictOur straight answer on the company after everything above, not on the trade. Quality, growth, price, risk and the long-term view.