New York, Jan 15, 2026, 16:52 (EST) — After-hours
- Penumbra shares surged roughly 12% following Boston Scientific’s announcement to acquire the company in a deal combining cash and stock
- The offer prices Penumbra at $374 per share, marking a premium over Wednesday’s closing price
- Traders are focused on the deal spread, the regulatory review process, and when shareholders will vote
Penumbra, Inc. shares jumped 11.8% to $350.49 in after-hours trading Thursday after Boston Scientific announced plans to acquire the clot-removal device maker in a roughly $14.5 billion deal. The stock reached an after-hours high of $369.84 but remained about $23 short of the $374 offer price, reflecting lingering merger risk and time before closing. 1
The deal comes as major medical device companies seek expansion in vascular care, where demand is rising for less invasive stroke and blood clot treatments. Thrombectomy — removing clots from blood vessels — remains a critical focus. BTIG analyst Ryan Zimmerman dubbed Penumbra “a growth asset” for the buyer in a note, while RBC Capital Markets’ Shagun Singh noted the company “has been considered a take-out candidate for some time now.” 2
Penumbra fueled optimism earlier with a preliminary update signaling another strong quarter. The company reported fourth-quarter revenue between $383.0 million and $384.8 million, marking about a 21% to 22% increase year-over-year. It also projected full-year 2025 revenue in the range of $1.401 billion to $1.403 billion. These numbers are unaudited and preliminary. 3
An SEC filing revealed that Penumbra signed the merger agreement on Jan. 14, detailing the election process: shareholders may opt for $374 in cash or 3.8721 Boston Scientific shares, with proration aiming for about 73% cash and 27% stock overall. The filing noted the deal’s closing depends on Penumbra shareholder approval, antitrust clearance via the Hart-Scott-Rodino process, and an effective S-4 registration statement for the shares to be issued — with no financing condition attached.
In another filing, Penumbra shared an internal email from CEO Adam Elsesser addressed to staff, calling the deal “a tremendous recognition” of the team’s efforts and assuring there would be “no immediate changes” to daily reporting structures. The filing also noted that Penumbra is set to operate as a standalone unit within Boston Scientific once the deal closes.
Traders are focusing on the spread in the next session. Simply put, the “deal spread” refers to the difference between Penumbra’s current trading price and the $374 offer. This gap can expand or contract depending on changes in perceived approval risk, timing, and the buyer’s share price.
Deals like this aren’t always smooth. Regulatory hurdles can slow things down, shareholder votes might throw a curveball, and if the acquirer’s stock drops, it can change the value for holders who choose shares. All these factors can force merger-arb funds to rapidly adjust their odds.
Boston Scientific’s Feb. 4 conference call on fourth-quarter results is the next major date to watch. Investors typically dig in on deal timing, financing, and integration details during these calls. 4
