Ultragenyx Pharmaceutical stock jumps on Fayuvi FDA approval and fresh Cantor Fitzgerald target

Ultragenyx Pharmaceutical Inc. stock (ISIN US74930A1043) has surged after the U.S. Food and Drug Administration granted full approval to the company’s gene therapy Fayuvi, with the shares closing at USD 14.50 on September 17, 2026, up 12.6 percent from the prior close of USD 12.88 on Nasdaq. As of September 18, 2026, investors are weighing both the regulatory milestone and new analyst targets that imply substantial upside from this post-approval price.

Fayuvi approval drives a historic move

According to Ultragenyx Pharmaceutical in its September 17, 2026 company release, the FDA granted standard full approval for Fayuvi (rebisufligene etisparvovec-hopf, also known as UX111) to treat pediatric patients with mucopolysaccharidosis type IIIA, or Sanfilippo syndrome Type A. The company highlights that Fayuvi is the first-ever FDA-approved treatment for Sanfilippo syndrome Type A, a progressive and fatal neurodegenerative disease, and notes that this is its second approved gene therapy as well as its sixth overall FDA approval.

As Reuters reported on September 17, 2026, Ultragenyx has set a U.S. list price of USD 3.95 million for Fayuvi as a one-time gene therapy, placing it among the world’s most expensive drugs. The same report notes that Ultragenyx shares closed 12.6 percent higher on Nasdaq on September 17, 2026, underscoring how quickly the market reacted to the approval and pricing news.

Stock reaction and valuation context

Per data summarized by The Economic Times on September 18, 2026, RARE stock closed at USD 14.50 on September 17, 2026, up 12.58 percent on the day, with more than 12.4 million shares changing hands versus an average volume of around 2.5 million. The article points out that despite the rally, the shares remain about 37 percent lower year-to-date, reflecting earlier weakness after a failed late-stage Angelman syndrome trial triggered a single-session decline of roughly 44 percent at the start of September 2026.

Additional trading color from MarketBeat on September 17, 2026 indicates that the stock traded as high as USD 14.24 intraday and last traded around USD 14.36, compared with a prior close of USD 12.88, implying an intraday gain of about 11.5 percent. The same overview notes increased trading activity, with mid-day volume up roughly 83 percent versus the average, and highlights that the stock had touched a 52-week low of USD 12.73 just one day before the approval, underlining how sharply sentiment turned on the regulatory outcome.

Analyst response and upside potential

Analysts moved quickly to update their views as the implications of the approval and the high list price became clearer. According to TradingView coverage on September 17, 2026, Ultragenyx shares gained about 13 percent in the regular session and extended gains by roughly 3 percent in after-hours trading after the Fayuvi decision, even though the stock remains well below earlier levels before the Angelman syndrome setback and is still trading near the low end of its 52-week range.

On September 18, 2026, Dow Jones Newswires on TradingView reported that Cantor Fitzgerald raised its price target on Ultragenyx Pharmaceutical stock to USD 39.00 per share from a previous USD 33.00 while maintaining an Overweight rating. A related note on TradingView emphasizes that this USD 39.00 target implies about 169 percent upside versus the September 17 close of USD 14.50, indicating that at least one major house now sees the approval as materially improving the company’s risk-reward profile.

The broader analyst backdrop described by MarketBeat remains supportive: across recent research, price targets range from USD 16.00 at the low end up to USD 58.00, with an average around USD 36.63 and most firms rating the stock Buy or Moderate Buy. Several houses had trimmed targets earlier in September 2026 to reflect the Angelman trial failure, for example cutting objectives from USD 83.00 to USD 37.00 or from USD 80.00 to USD 36.00, but the latest Cantor Fitzgerald move shows how quickly views can adjust when a commercial gene therapy asset receives full approval and premium pricing.

Fundamental outlook and upcoming earnings

On the fundamentals side, investors now have both a major new product and updated expectations for the near-term results. As Zacks noted on September 18, 2026, consensus forecasts for Ultragenyx’s upcoming quarterly report point to a loss of USD 0.65 per share, which would represent a 64.1 percent improvement versus the prior-year quarter, alongside expected revenue of USD 185.2 million, up 15.8 percent year-over-year. Zacks adds that the consensus EPS estimate has been revised about 6.4 percent higher over the last 30 days, underscoring how analysts have already begun to bake in better profitability trends even before Fayuvi sales ramp.

Clinical data supporting the approval are also a critical part of the fundamental story. According to The Economic Times, Ultragenyx reported that treated children maintained or improved cognitive function between ages two and five, with a 23.5-point advantage on a standard cognitive score relative to an untreated natural-history group. Zacks likewise highlights nearly eight years of clinical data backing the approval, including the same 23.5-point higher mean change in Bayley-III cognitive raw score versus a natural-history cohort, reinforcing the durability and magnitude of benefit regulators and clinicians will focus on as the therapy moves into commercial use.

Risk factors and what investors will watch next

Despite the clear positive surprise from the FDA and the sharp one-day gain, several risks remain in view. As The Economic Times points out, the stock is still around 37 percent lower year-to-date, largely due to the failed late-stage Angelman syndrome trial that sent the shares down around 44 percent in a single session in early September 2026. That episode highlighted the binary nature of late-stage rare-disease programs and the sensitivity of Ultragenyx’s valuation to pipeline setbacks, a factor investors will continue to monitor across other assets.

Furthermore, TradingView notes that Ultragenyx expects Fayuvi to reach qualified U.S. treatment centers within 30 to 60 days, but the USD 3.95 million per-patient wholesale acquisition cost means payer negotiations and access programs will be central to the therapy’s actual uptake. For investors, the key questions now are how quickly revenue from Fayuvi can ramp, how much of the priority review voucher value Ultragenyx can monetize, and how effectively management can reinvest proceeds into the broader gene therapy and rare-disease pipeline to offset past trial disappointments.

Stock level and market data

From a market perspective, Ultragenyx Pharmaceutical stock’s latest confirmed closing reference comes from Nasdaq trading on September 17, 2026, when the shares ended at USD 14.50, up 12.6 percent on the day, after having touched a 52-week low of USD 12.73 just one day earlier. With Cantor Fitzgerald’s new USD 39.00 target now roughly 169 percent above that closing price, the gap between current trading levels and bullish analyst scenarios remains wide, and the next quarterly report with the expected USD 185.2 million in revenue will be a key checkpoint for whether the recent approval-driven optimism can translate into sustained fundamental momentum.

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