The major indices actually had a good Thursday — the Dow, S&P 500, and Nasdaq all closed higher as Treasury yields eased on dovish Fed commentary. But scroll past the headline numbers and today’s list of top losing stocks today tells a very different story: a rare-disease biotech lost nearly half its market value on a failed drug trial, a fiber-optics favorite got branded “the worst performer in the S&P 500” despite beating every estimate, and a Swedish EV maker got walloped by a U.S. trade crackdown most investors never saw coming. From consumer pantry staples to clinical-stage biotech, here are the 10 stocks that had the roughest session in the market today.

Thursday’s Broader Market Context:

Even with the broader market in the green, decliners piled up in specific corners — biotech, networking, autos, and consumer staples all had brutal individual stories today.

1. Ultragenyx Pharmaceutical (RARE) | Closed $14.55, Down 45.16%

A Failed Angelman Syndrome Trial Erases Years of Optimism

Ultragenyx’s investigational Angelman syndrome therapy apazunersen failed to meet its primary and key secondary endpoints in the Phase 3 Aspire study, sending shares crashing more than 45% and forcing the company into a strategic review.

Full Data & Technical Snapshot:

Why It Tanked: The Phase 3 Aspire study did not achieve its primary endpoint (change in Bayley-4 cognitive score) nor its key secondary endpoint, and Ultragenyx confirmed it will pursue “significant expense reductions” while pivoting focus to its commercial portfolio, including the recently FDA-approved gene therapy Genglycos.

Bull Case: JPMorgan sees fundamental value in Ultragenyx’s commercial business alone in the mid-$20s per share, and a favorable FDA decision on UX111 for MPS IIIA is expected later this month — a potential partial offset to today’s damage.

Bear Case: The failure raises real questions about Ultragenyx’s parallel Aurora trial using a similar mechanism, and the company remains cash-burning with a negative gross margin amid an uncertain strategic review.

Technicals: Shares broke decisively below their prior 52-week low of $18.29 on the heaviest volume of the year; no historical support exists at current levels given the unprecedented single-day drop.

Forecast: The UX111 regulatory decision later this month is now the single most important near-term catalyst for shares to stabilize.

Why This Matters: A single failed Phase 3 readout wiping out nearly half a company’s market value in hours is a stark reminder of binary clinical-trial risk — even for a biotech with a genuinely profitable commercial business underneath.

2. Aptevo Therapeutics (APVO) | Down 17.3%

Good News, Bad Reaction — A Micro-Cap Biotech’s Strange Day

In one of today’s most counterintuitive moves, Aptevo Therapeutics shares slid 17.3% to around $2.15 even as the company disclosed a 93% clinical benefit rate for its mipletamig triplet therapy in frontline acute myeloid leukemia patients with TP53 mutations — one of the hardest-to-treat AML subtypes.

Full Data & Technical Snapshot:

Why It Tanked: Despite genuinely encouraging data — a remission rate nearly double the historical benchmark — the tiny sample size (just 14 evaluable patients) appears to have driven profit-taking after a run-up into the data readout, a common pattern for micro-cap biotech names trading on thin volume and high short-term speculation.

Bull Case: A 93% clinical benefit rate and 79% remission rate in one of AML’s most treatment-resistant genetic subtypes is a genuinely differentiated result, and the stock’s average price target implies enormous theoretical upside from current micro-cap levels.

Bear Case: Small sample sizes in early-stage trials carry real statistical risk, Aptevo remains a cash-constrained clinical-stage company, and today’s “sell the news” reaction shows the market isn’t yet convinced the data will hold up in larger cohorts.

Technicals: The stock remains extremely thinly traded and volatile, with the kind of wide daily swings typical of sub-$10 million market cap biotech names.

Forecast: Continued frontline AML data readouts from the ongoing RAINIER trial will be the key driver — a larger confirmatory dataset showing similar remission rates could reverse today’s skepticism quickly.

Why This Matters: Aptevo’s paradoxical drop on genuinely positive data is a reminder that in micro-cap biotech, “buy the rumor, sell the news” can apply even when the news itself is good.

3. Polestar Automotive (PSNY) | Down 16%

Washington’s China Crackdown Catches Up With Tesla’s Rival

Polestar shares plunged 16% to around $10 after the Swedish EV maker cut its full-year delivery forecast, hurt by a U.S. crackdown on Chinese-linked vehicles that has already forced the company out of the American market.

Full Data & Technical Snapshot:

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Why It Tanked: The Trump administration refused to grant Polestar — majority-owned by China’s Geely Holding — authorization to sell vehicles in the U.S. from model year 2027 onward, part of a broader crackdown on Chinese-linked automakers. Polestar now expects annual volume growth of just low-to-mid single digits in 2026, down sharply from a prior forecast of low double-digit growth (roughly 66,000–71,000 cars).

Bull Case: The net loss narrowed by more than half year-over-year even amid the U.S. exit, and the average analyst price target of $15 still implies significant upside — some analysts see the sell-off as overdone given Polestar’s remaining European and Chinese market opportunities.

Bear Case: Losing the entire U.S. market is a structural, not cyclical, headwind, and majority ownership by Geely leaves Polestar entangled in broader U.S.-China trade tensions that show no signs of resolving soon.

Technicals: Shares are trading near multi-year lows, with the stock having round-tripped from a post-SPAC-merger high near $13.36 down toward single digits over its public life.

Forecast: Without a path back into the U.S. market, Polestar’s growth story now depends almost entirely on European demand and its upcoming Polestar 5 and 6 launches to offset the lost American revenue base.

Why This Matters: Polestar’s collapse is a preview of how geopolitically-entangled ownership structures can create sudden, severe regulatory risk for global automakers — a risk other China-linked companies may face as trade tensions persist.

4. Ciena Corporation (CIEN) | Down 11%

The “Worst Performer in the S&P 500” — Despite Beating Every Estimate

In a session that echoed Broadcom’s own earnings reaction the night before, Ciena reported record fiscal third-quarter results with adjusted EPS of $2.11 versus a $1.73 consensus and revenue of $1.67 billion versus $1.64 billion expected — and the stock still fell 11%, reportedly making it the worst performer in the entire S&P 500 on the day.

Full Data & Technical Snapshot:

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Why It Tanked: Despite raising full-year guidance and beating on every headline metric, supply constraints on specialized components — including pump lasers — remain a structural concern flagged by analysts as a risk to Ciena’s ability to convert its backlog on schedule, while the stock’s massive run-up over the past year (from a 52-week low near $92 to over $600) left valuation stretched heading into the print.

Bull Case: Ciena’s positioning in AI-driven optical networking and data-center interconnects, combined with hyperscaler design wins and genuinely raised guidance, supports the long-term growth thesis — Needham’s revised $520 target still implies substantial upside.

Bear Case: A stock that ran from roughly $92 to over $600 in a year was priced for flawless execution, and any hint of component-driven “revenue lumpiness” was enough to trigger profit-taking regardless of the actual beat.

Technicals: Shares fell well below recent trading levels after gapping down at the open; the wide 52-week range ($92.46–$637.51) reflects just how volatile this AI-networking name has been all year.

Forecast: With guidance raised and demand fundamentals intact, today’s drop looks more like valuation-driven profit-taking than a change in the underlying growth story — a pattern that may reverse if backlog conversion proves supply constraints aren’t as severe as feared.

Why This Matters: Ciena joins Broadcom and HPE this week in a growing list of AI infrastructure names getting sold off despite genuine beats — a sign the market’s bar for these stocks has become nearly impossible to clear.

5. Planet Labs PBC (PL) | Closed $18.17, Down 9.11%

A Satellite Data Company Sinking Into Its Own Earnings Report

Planet Labs shares fell heading into its own fiscal second-quarter 2027 earnings report, due after Thursday’s close, with the stock trading well below its 20-day, 50-day, 100-day, and 200-day moving averages heading into the print.

Full Data & Technical Snapshot:

Why It Tanked: Pre-earnings jitters compounded a technically bearish setup — the stock confirmed a “death cross” (50-day moving average crossing below the 200-day) in August, and shares are down more than 54% over the past 90 days even after a satellite milestone earlier this week (its Tanager-2 hyperspectral satellite reached Vandenberg Space Force Base ahead of a planned SpaceX launch).

Bull Case: A one-year total shareholder return above 200% shows the underlying growth story remains intact, and a $34.90 average analyst target suggests today’s price may significantly undervalue accelerating global demand for daily Earth-observation data.

Bear Case: The stock remains unprofitable with a widening loss (−100.4% YoY), and the technical picture is unambiguously bearish heading into a report that could either confirm or worsen that trend.

Technicals: Trading 13.8% below its 20-day SMA, 19.6% below its 50-day SMA, 37.7% below its 100-day SMA, and 27.3% below its 200-day SMA — a comprehensively weak setup.

Forecast: Tonight’s earnings commentary on the path to sustained positive free cash flow is the key variable that could either begin repairing the technical damage or extend the sell-off further.

Why This Matters: Planet Labs’ slide despite genuine operational progress (satellite launches, government contracts) shows how unforgiving markets have become toward unprofitable growth stories regardless of execution quality.

6. Campbell’s Company (CPB) | Closed $21.26, Down 10.8%

A Dividend Cut and Weak Guidance Sour a Pantry-Staple Stock

Campbell’s shares fell 10.8% after the packaged food company met Wall Street’s Q4 estimates but issued weaker-than-expected full-year 2027 profit guidance and announced a dividend reset to accelerate debt reduction.

Full Data & Technical Snapshot:

Why It Tanked: Operating margin contracted sharply to 0.2% from 11.6% a year earlier, and gross margin dropped 3.4 percentage points to 27.3%, with management explicitly citing weak consumer spending and cutting the quarterly dividend to speed up debt reduction — a signal that typically spooks income-focused investors in the consumer staples space.

Bull Case: At roughly 37.5% below its 52-week high, CPB now trades at a valuation that prices in significant pessimism, and the dividend reset — while painful — gives the company more balance-sheet flexibility to invest in its core brands.

Bear Case: Consecutive quarters of declining organic sales and margin compression suggest structural demand weakness in packaged foods, not a one-off issue, and Barclays maintains an outright Sell rating on the stock.

Technicals: Shares are trading well below both their 52-week high and their year-ago levels, in a well-established downtrend that today’s news accelerated rather than reversed.

Forecast: With guidance already reset and the dividend cut absorbed, the path to stabilization likely depends on whether cost-savings initiatives (targeting $375 million by fiscal 2028) can offset continued volume softness.

Why This Matters: Campbell’s is part of a broader pattern this week of consumer staples names (alongside Tyson Foods) getting punished for weak guidance even in a sector traditionally viewed as defensive.

7. Tyson Foods (TSN) | Down ~7%

Historic Cattle Shortage Squeezes America’s Biggest Meat Producer

Tyson Foods shares fell roughly 7% after the company cut its fiscal 2026 revenue growth outlook to 1.5%–2% from a prior 2.5%–3.5%, citing severe margin compression from one of the most extreme cattle shortages in U.S. history.

Full Data & Technical Snapshot:

Why It Tanked: Management pointed directly to volatile cattle prices and a historically severe cattle shortage as the driver of the guidance cut, warning that lower cattle prices are also expected to hit the reported value of live cattle inventories on the balance sheet — a double hit to both operating margins and asset values.

Bull Case: Tyson’s diversified segment mix (Beef, Pork, Chicken, Prepared Foods) provides some natural hedging against a single-protein commodity shock, and a dividend yield near 3.5% offers income support during the downturn.

Bear Case: Cattle supply cycles typically take multiple years to normalize, meaning today’s guidance cut may not be a one-quarter issue — margin pressure in the Beef segment could persist well into 2027.

Technicals: The stock is trading in the lower half of its 52-week range following today’s decline, reflecting sustained pressure from commodity-driven earnings volatility.

Forecast: Beef segment margins are unlikely to recover meaningfully until the U.S. cattle herd rebuilds — a process historically measured in years, not quarters — making this a multi-year overhang rather than a short-term stumble.

Why This Matters: Tyson’s guidance cut is a reminder that even the largest, most diversified food companies remain exposed to raw commodity supply shocks that can override otherwise stable demand trends.

8. Victoria’s Secret & Co. (VSXY) | Down 12%

Beat-and-Raise Wasn’t Enough for This Retail Turnaround Story

Victoria’s Secret shares fell 12% despite posting mixed-but-largely-positive Q2 results, with adjusted EPS of $0.95 topping the $0.77 estimate and same-store sales up 9%, in line with expectations — but total sales of $1.61 billion narrowly missed consensus.

Full Data & Technical Snapshot:

Why It Tanked: Despite an EPS beat and a raised full-year sales outlook, the narrow top-line miss on Q2 sales appears to have outweighed the otherwise solid quarter — a pattern consistent with today’s broader theme of the market punishing “good but not perfect” results across multiple names.

Bull Case: A raised full-year sales guide and consistent same-store sales growth of 9% suggest Victoria’s Secret’s ongoing brand turnaround is genuinely working, not just a one-quarter blip.

Bear Case: A retailer with this much turnaround optimism already priced in needs to beat on every single line item, and even a narrow top-line miss can trigger disproportionate selling when expectations are elevated.

Technicals: Today’s drop pulls shares back toward recent support levels established earlier in the turnaround rally, testing whether the broader uptrend remains intact.

Forecast: With full-year guidance raised despite the Q2 sales miss, the turnaround thesis remains technically supported — the next quarter’s same-store sales trend will be the key confirmation point.

Why This Matters: Victoria’s Secret’s reaction extends today’s pattern across sectors — from tech to retail — where genuinely solid results are getting sold first and asked questions later.

9. Methode Electronics (MEI) | Down 12%

A Sales Beat That Still Fell Short on Profitability

Methode Electronics shares fell 12% despite Q1 sales rising 10% and beating analyst expectations, as adjusted EBITDA declined year-over-year after the company lost the contribution of its divested dataMate business and increased investments in talent and capabilities.

Full Data & Technical Snapshot:

Why It Tanked: Even though top-line sales beat expectations, the year-over-year decline in adjusted EBITDA — driven partly by the divestiture of the dataMate business and partly by increased spending on talent and capabilities — raised concerns about near-term profitability trajectory, overshadowing the otherwise solid revenue growth.

Bull Case: Management affirmed its fiscal 2027 guidance despite today’s EBITDA miss, suggesting the investments weighing on near-term profitability are viewed internally as temporary rather than structural.

Bear Case: A 10% sales beat that still produces a 12% stock decline signals the market is prioritizing margin trajectory over top-line growth right now — a difficult dynamic for a company mid-transition after a business divestiture.

Technicals: The stock’s sharp single-day decline on beat-but-miss dynamics mirrors the pattern seen at larger names like Ciena and Broadcom today, suggesting a market-wide sensitivity to margin quality over headline beats.

Forecast: With full-year guidance unchanged, the next few quarters will need to show the talent and capability investments translating into either accelerating revenue growth or margin recovery to validate today’s spending increase.

Why This Matters: Methode’s reaction shows that even smaller industrial and electronics names aren’t immune to the “beat isn’t enough” dynamic dominating this earnings season — margin quality is now scrutinized as closely as revenue growth at every market-cap tier.

10. Phreesia (PHR) | Down ~4%

A Healthcare Tech Beat That Still Left the Guidance Unchanged

Phreesia shares fell after the healthcare technology company reported Q2 revenue and EBITDA that came in 0.3% and 7.2% ahead of consensus respectively, driven by strong cost control — but management held full-year guidance flat rather than raising it.

Full Data & Technical Snapshot:

Why It Tanked: Despite a genuine EBITDA beat driven by strong cost discipline, management’s decision to hold full-year guidance flat — rather than raise it to reflect the beat — signaled to investors that the company is prioritizing reinvestment in newer growth initiatives (ProviderConnect and AccessOne) over near-term profitability upside, a trade-off the market reacted to cautiously today.

Bull Case: Strong cost control driving a 7.2% EBITDA beat shows genuine operating discipline, and accelerated investment in ProviderConnect and AccessOne could expand Phreesia’s total addressable market if the newer product lines gain traction.

Bear Case: Holding guidance flat after a beat — rather than raising it — often reads as a subtle negative signal to growth investors, even when framed as a deliberate reinvestment decision.

Technicals: Today’s modest 4% decline is the smallest move among today’s list of decliners, reflecting a more measured market reaction relative to the sharper drops seen at consumer and biotech names.

Forecast: The success of ProviderConnect and AccessOne over the next several quarters will determine whether today’s “flat guidance” decision proves to be prudent reinvestment or a missed opportunity to capitalize on cost-control momentum.

Why This Matters: Phreesia’s relatively modest decline compared to today’s more dramatic losers shows that not every “beat but no raise” story gets punished equally — the market still distinguishes between genuine reinvestment stories and outright disappointments.

Sector Sentiment Snapshot & Forecast

Today’s losers reveal a clear, cross-sector pattern: the market punished “good but not flawless” results almost indiscriminately. Ciena, Victoria’s Secret, and Methode Electronics all beat headline estimates and still fell double digits, echoing the same dynamic that hit Broadcom and HPE in the broader trending-stocks conversation today. Biotech delivered the day’s most extreme swings — Ultragenyx’s binary trial failure (−45%) and Aptevo’s paradoxical “good news, bad reaction” drop (−17%) both underscore how unforgiving clinical-stage and rare-disease biotech investing remains. Consumer staples took a beating as both Campbell’s and Tyson Foods cut guidance for entirely different reasons (a dividend reset and weak demand vs. a historic cattle shortage), showing that even traditionally defensive sectors aren’t immune to sharp single-day drops. And Polestar’s collapse stands out as a reminder that geopolitical and regulatory risk can strike a stock overnight, independent of any operational miss.

With Broadcom and HPE both having stumbled on Wednesday night and today’s list confirming the pattern extends well beyond AI infrastructure into retail, food, and networking, expect continued volatility around every earnings report this season — the bar for “good enough” has rarely been higher.

At a Glance: Today’s Top 10 Losing Stocks

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Disclaimer: This publication is entirely for informational and journalistic purposes and does not constitute formal financial, investment, or legal advice. All market investments carry inherent risks of capital loss, and clinical-stage biotech and micro-cap stocks carry elevated risk. Stock prices, percentage moves, and market data cited reflect figures available at the time of publication and are subject to change. Some prices in this article are approximate, based on available reporting at the time of writing, given real-time data limitations for smaller-cap names. Analyst price targets and ratings are third-party estimates and do not guarantee actual results. Planet Labs reports earnings after this publication — actual results and subsequent market reactions may differ significantly from the expectations described here. Always complete independent due diligence prior to executing equity trades.

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Kasia Davis

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