Key Highlights

  • Glaukos (NYSE:GKOS) surged 33.7% on October 29, 2026, the largest gain in a closing list of movers. Alnylam (NASDAQ:ALNY) fell 25.1% the same day, and the cause of both moves was not confirmed.
  • ADT (NYSE:ADT) jumped about 34% to roughly USD 9.93 on October 29, 2026 after Thrive Holdings offered USD 10 per share in cash, a bid valuing the company at about USD 7.6 billion. Terms come from one account.
  • Crocs (NASDAQ:CROX) soared about 25% on October 29, 2026 to its highest level in more than two years. HeyDude Revenue rose 6.1% to USD 170 million, and the company raised 2026 guidance for the third time.
  • Sprouts Farmers Market (NASDAQ:SFM) fell between 18% and 22.6% on October 29, 2026 after the grocer cut its fourth-quarter outlook, with published accounts giving different figures. Management reportedly warned that price cuts will hurt profit into next year.

Glaukos (NYSE:GKOS): Largest gain, no confirmed cause

Glaukos (NYSE:GKOS), a maker of eye-care devices and therapies, surged 33.7% on October 29, 2026. Alnylam (NASDAQ:ALNY), a pioneer in RNA interference medicines, fell 25.1%. Both appear in a single closing list of S&P-adjacent stocks, so the figures carry a one-account flag. Moves of 25% to 34% in one session are rare for companies of this size, and usually signal company-specific news such as results, guidance or a clinical or regulatory update. However, the cause was not verified for either company, so this article treats the moves as facts and the reasons as unknown. Neither company's results, guidance or analyst notes were confirmed in the published accounts, so even the nature of the news behind each move is unknown. The closing list is described as covering the biggest winners and losers, which makes the pairing a market-wide snapshot. In MedTech and biotech, a single data point can change how investors value future revenue. For a device maker, a change in procedure volumes, reimbursement or product launches can shift Earnings forecasts. For an RNAi biotech, product sales, trial readouts or competitive data can do the same. A drop of 25.1% typically means expectations were high and something fell short, while a gain of 33.7% suggests results or guidance beat a low bar.

ADT (NYSE:ADT): Cash bid under USD 10

ADT (NYSE:ADT) announced on October 29, 2026 that Thrive Holdings offered USD 10 per share in an all-cash transaction valuing the company at about USD 7.6 billion. The stock jumped about 34% to roughly USD 9.93. The existence of a company 8-K filing and proxy filings is confirmed, but their text could not be opened, so the terms stated here rest on one published account. The premium to the previous close, the closing timeline, the financing and any conditions are not verified, and none is stated. The jump of about 34% is itself a signal that the offer was well above the price before the announcement, though the exact premium was not retrieved. When an all-cash offer is announced, the target's stock usually trades slightly below the offer price. The difference, called the spread, compensates traders for waiting until the deal closes and for the risk that it fails. Here ADT (NYSE:ADT) at roughly USD 9.93 against USD 10 leaves about USD 0.07, or 0.7%, per share, which is simple arithmetic on two published numbers. A spread that small implies the market sees a high chance of completion and a short wait, though that is an inference and not a company statement.

Crocs (NASDAQ:CROX): Two-year high, third raise

Crocs (NASDAQ:CROX) reported third-quarter results on October 29, 2026, and the stock soared about 25% to its highest level in more than two years. Three published accounts confirm the move and the main drivers. HeyDude, the company's second brand, grew revenue by 6.1% to USD 170 million, which is the first increase in six quarters. Management also raised its 2026 outlook for the third time this year. The consensus estimates, the new guidance ranges and the figures for the main Crocs Brand were not retrieved, so none is stated here. A one-day gain of about 25% is large for a consumer company and is why the shares drew attention. A brand that returns to growth after six quarters of declines changes how investors judge the business. HeyDude is the company's second brand, and six quarters without growth had kept attention on it. A rise of 6.1% is modest in size, and it comes from a small base, yet the direction matters because it suggests the brand may have stopped losing share. For Crocs (NASDAQ:CROX), a third guidance raise in one year also matters, since repeated upgrades usually mean management set cautious targets.

Sprouts Farmers Market (NASDAQ:SFM): Outlook cut, wide range

Sprouts Farmers Market (NASDAQ:SFM) fell between 18% and 22.6% on October 29, 2026 after lowering its fourth-quarter outlook. Reported EPS guidance of USD 0.47 to 0.51 was compared with an expected figure of about USD 1.21. That comparison does not stand up well, since a guide of roughly half the consensus would imply a far larger collapse than the verified moves, so the USD 1.21 consensus is treated as not confirmed. What is consistent is the direction: a guidance cut and a steep share decline. The different figures likely reflect different times of day. The company release is the best place to confirm the exact wording and ranges of the revised outlook. Grocers sometimes lower prices to defend traffic against rivals, and the trade-off is that each sale carries a thinner margin. Sprouts said price cuts will hurt profit into next year, which signals that the pressure is not confined to one quarter. Investors had priced the stock for steady growth, so a warning that profitability will stay under pressure can reset valuation quickly.

Where Things Stand

The answer is that the largest moves of the session had very different drivers. ADT has an announced cash offer, Crocs has a growth return at HeyDude and a third guidance raise, Sprouts has a lowered outlook, and Glaukos (NYSE:GKOS) has no confirmed cause at all. Large moves are not all alike: a bid caps the upside, a guidance raise tests the next quarter and a cut can compound. The next catalysts are the ADT proxy, the Crocs report, Sprouts releases and any news that explains Glaukos (NYSE:GKOS). This is not Investment advice.