Despite reporting strong fourth-quarter (Q4) organic sales growth of $5.29 billion, up 12.7% year-on-year, Boston Scientific Corp. saw its shares plunge more than 17% in early trading. Investors appeared disappointed by weaker U.S. sales in the electrophysiology and Watchman businesses, two of the company’s growth engines, and concern over the 2026 organic growth guidance provided by management of 10% to 11%, down from the 15.8% seen in 2025.