Boston Scientific Crashes to a 4-Year Low: A Cyberattack Just Cut Its Guidance Again

Boston Scientific stock crashed on Wednesday, October 28, 2026, after the medical-device giant cut its full-year guidance again — blaming the lasting fallout from an August cyberattack that disrupted its factories and shipments. Shares fell about 7% to around $41.87 in Wednesday trading, after dropping more than 9% in premarket action toward a four-year low, even though its third-quarter sales and earnings actually beat Wall Street forecasts.

What happened

Boston Scientific reported third-quarter net sales of $5.14 billion, up 1.5% from a year earlier and ahead of the $5.06 billion analysts surveyed by FactSet had expected. Adjusted earnings were 73 cents a share, down from 75 cents a year ago but slightly ahead of the 72 cents Wall Street expected. Profit attributable to shareholders was $582 million, or 40 cents a share, compared with $755 million, or 51 cents a share, a year earlier.

The numbers themselves were not the problem. The outlook was. The company now expects full-year sales to grow about 4.25% on a reported basis — about 3.75% organically — down from the 5.5% to 6.5% growth it forecast at the end of July. It cut its full-year adjusted earnings forecast to $3.16 to $3.18 a share, from $3.28 to $3.32 previously.

For the fourth quarter, Boston Scientific expects sales to decline 1% to 3%, with adjusted earnings of 77 to 79 cents a share. Wall Street had been expecting sales growth and earnings of about 83 cents a share, according to FactSet.

Why it's blowing up

The story traders are sharing is not a normal earnings miss. In late August, Boston Scientific suffered a cybersecurity incident that disrupted manufacturing, order processing and customer shipments across most of its divisions. In September, the company warned it was unlikely to meet its third-quarter and full-year guidance because of that incident — and Wednesday's results confirmed the warning was accurate.

Analysts noted the disruption was broad. Evercore ISI pointed to impacts across electrophysiology, interventional cardiology and vascular, cardiac rhythm management, endoscopy and urology. Segment results showed the strain: MedSurg sales grew just 0.6% and cardiovascular sales rose 1.9%, while a 13.1% jump in neuromodulation helped offset a decline of less than 1% in endoscopy and a 3.2% slide in urology.

The stock was already fragile before Wednesday. Shares had fallen about 53% this year as of Tuesday's close, pressured by softer demand for its Watchman device and tougher competition in key cardiac franchises. A guidance cut tied to a cyberattack, landing on a stock already down by half, is why the move turned viral in market circles within hours.

Key facts

• Stock move: Shares fell about 7% on Wednesday to around $41.87, after a premarket drop of more than 9% that threatened a four-year low.
• Q3 sales: $5.14 billion, up 1.5% year over year, beating the $5.06 billion FactSet consensus.
• Q3 adjusted EPS: 73 cents, ahead of the 72 cents expected, but down from 75 cents a year ago.
• New full-year guide: Sales growth of about 4.25%, down from 5.5% to 6.5%; adjusted EPS of $3.16 to $3.18, down from $3.28 to $3.32.
• Q4 guide: Sales down 1% to 3%, adjusted EPS of 77 to 79 cents, versus about 83 cents expected.
• Cause: A late-August cybersecurity incident disrupted manufacturing and shipments; the company warned in September that its earlier guidance was unlikely to be met.

Chief Executive Mike Mahoney acknowledged the strain, saying this has been a challenging year for Boston Scientific and that he remains confident in the company's long-term strategy, according to the Wall Street Journal's earnings coverage.

What's next

The next question for markets is whether the fourth-quarter decline is the end of the cyberattack drag or the start of a longer reset. Investors will watch whether shipments and order processing are fully normalized, whether the affected cardiac and endoscopy franchises recover, and whether management can rebuild confidence after a year in which the stock has lost more than half its value. For now, Wednesday's reaction shows a simple market lesson: beating the quarter you just reported does not protect a stock when the guidance for the quarters ahead gets cut.

Sources: Barron's, The Wall Street Journal, Investor's Business Daily, Seeking Alpha. This article reports market news and is not financial advice.

FAQ

Why did Boston Scientific stock fall on October 28, 2026?

It fell because the company cut its full-year sales and earnings guidance, citing the lasting impact of an August cyberattack, even though its third-quarter results beat forecasts.

What was Boston Scientific's new 2026 guidance?

It now expects full-year sales growth of about 4.25% and adjusted earnings of $3.16 to $3.18 a share, down from 5.5% to 6.5% growth and $3.28 to $3.32 a share previously.

How did Boston Scientific do in Q3 2026?

Sales rose 1.5% to $5.14 billion, beating the $5.06 billion expected, and adjusted earnings were 73 cents a share, just ahead of the 72 cents analysts expected.

What did the cyberattack disrupt?

The late-August incident disrupted manufacturing, order processing and customer shipments across most divisions, and the company warned in September that it would likely miss its earlier guidance.