Boston Scientific Buys Penumbra for $14.5 Billion
Medical device giant acquires stroke and clot treatment maker at 19% premium. Deal expands cardiovascular portfolio with mechanical thrombectomy.
Boston Scientific is making its biggest acquisition ever.
The medical device company announced Thursday it will acquire Penumbra for approximately $14.5 billion in a cash-and-stock deal. Penumbra shareholders will receive $374 per share—a 19% premium to Wednesday's close—with the option to take cash or Boston Scientific stock, subject to proration.
Penumbra jumped 13% in premarket trading to near the deal price. Boston Scientific fell 2% as investors digested the financing requirements.
Deal Structure
The transaction breaks down to roughly 73% cash and 27% stock. Boston Scientific will fund the $11 billion cash portion through existing reserves and new debt, adding leverage to a balance sheet that's been relatively conservative.
Shareholders electing stock receive 3.8721 Boston Scientific shares per Penumbra share—a conversion ratio that locks in the current premium regardless of where BSX trades before closing.
The deal is expected to be $0.06-0.08 dilutive to Boston Scientific's adjusted EPS in year one, neutral to slightly accretive in year two, and more accretive afterward. That's a typical pattern for large strategic acquisitions that require integration spending upfront.
Why Penumbra?
Penumbra makes devices for removing blood clots from veins and arteries. Its mechanical thrombectomy systems treat strokes, pulmonary embolisms, and deep vein thrombosis—conditions where fast clot removal can mean the difference between full recovery and permanent disability.
The neurovascular and peripheral vascular markets represent what Boston Scientific calls "key strategic adjacencies." The company already dominates in cardiac rhythm management and interventional cardiology. Penumbra fills gaps in its vascular portfolio.
Adam Elsesser, Penumbra's CEO and chairman, will join Boston Scientific's board upon closing. That kind of leadership continuity suggests the deal was negotiated collaboratively rather than as a hostile takeout.
Healthcare M&A Context
The acquisition comes amid renewed activity in healthcare dealmaking after a two-year slowdown. Rising interest rates and regulatory uncertainty had cooled the market, but 2025 saw a revival as the Fed cut rates and acquirers gained confidence in financing conditions.
Boston Scientific has been on an acquisition spree, adding bolt-on deals throughout 2025 to supplement organic growth. Penumbra is different in scale—this is a platform acquisition that transforms the company's competitive position in vascular intervention.
The 19% premium sits at the lower end of historical healthcare M&A premiums, which typically range from 20-40%. That suggests Penumbra's board saw strategic value in the combination beyond just price, or that alternative bidders didn't materialize.
What Traders Should Watch
The deal requires Penumbra shareholder approval and standard regulatory clearances. Management expects closing sometime in 2026, though specific timing wasn't provided.
For the broader healthcare sector, the Penumbra deal signals that large-cap acquirers are willing to pay up for growth in specialized markets. Medical device companies with defensible technology and clear clinical value remain attractive targets.
Boston Scientific's stock reaction—down 2% on a day the market is rallying—reflects concern about near-term dilution and integration execution. The company has a strong track record with acquisitions, but $14.5 billion is still a significant bet that needs to pay off over multiple years.
Penumbra holders face a decision: take the cash at $374, convert to Boston Scientific stock, or some mix. The answer depends on your view of BSX's growth trajectory and whether the deal premium adequately compensates for giving up Penumbra's standalone upside.