William Lewis, Chair and CEO of Insmed Inc, sold nearly $1.7 million worth of company stock on January 20, 2026, while also exercising options for additional shares. This activity took place amid robust recent sales figures for Insmed’s key drugs Brinsupri and ARIKAYCE, and ahead of an upcoming earnings report.
Key Points
- William Lewis, Insmed’s Chair and CEO, sold 11,699 shares valued at $1.7 million on January 20, 2026, at prices close to the trading range of the stock.
- Lewis also exercised options to acquire 10,699 shares through previously granted stock options, adding shares at strikes significantly below the market price.
- Insmed reported strong 2025 sales growth for its drugs Brinsupri and ARIKAYCE, with Brinsupri exceeding expectations by 116% in Q4 and ARIKAYCE showing 19% year-over-year revenue growth.
- Insmed's market capitalization is $34.21 billion, and analysts maintain a strong buy consensus, reflecting confidence in the company's performance and prospects.
On January 20, 2026, William Lewis, the Chair and Chief Executive Officer of Insmed Inc (NASDAQ:INSM), completed the sale of 11,699 shares of the biotech firm’s common stock. The shares traded between prices of $156.80 and $160.70 each, aggregating to approximately $1,700,411. This transaction price aligns closely with Insmed's then-current trading price of $160.39. Over the last twelve months, Insmed's stock has appreciated significantly, delivering a cumulative return of 106%. Despite this, technical metrics such as the Relative Strength Index (RSI) suggest the stock might be approaching oversold conditions, according to InvestingPro data.
Concurrently on the same day, Lewis exercised stock options to obtain 10,699 shares, involving strike prices of $30.46 and $17.16. The total value of shares obtained through this option exercise was $266,839. Post these transactions, Lewis retains direct ownership of 306,891 Insmed shares. Additionally, he holds an indirect stake via trusts, including 233,924 shares through the Katie Procter Dynasty Trust and 50,500 shares through the William Lewis Family Legacy Trust.
Insmed's market capitalization stands at $34.21 billion amidst a strong buy consensus from analysts. Investors seeking in-depth analysis can find detailed research in the InvestingPro Research Report, which covers Insmed alongside over 1,400 other US-listed equities.
It is notable that these insider trades were made under a prearranged 10b5-1 trading plan, adopted on September 4, 2025. Insmed is set to report its next earnings on February 19, 2026, which may provide further insights into recent insider activity.
In other corporate updates, Insmed recently announced impressive financial results driven by its flagship drug Brinsupri. Fourth-quarter 2025 sales of Brinsupri reached $144.6 million, exceeding analyst expectations by 116%, reflecting a strong market introduction. Full-year 2025 Brinsupri sales totaled approximately $172.7 million.
Established therapy ARIKAYCE also performed well, with unaudited global revenues of $433.8 million reported for 2025. This result surpassed company guidance and represented 19% year-over-year growth. Insmed anticipates ARIKAYCE sales to climb further in 2026, forecasting revenues between $450 million and $470 million.
Despite the positive company-specific data, RBC Capital cautions the biotech sector faces potential headwinds in 2026, including biosimilar and generic drug competition that may pressure market dynamics. Nevertheless, Insmed’s recent achievements highlight its robust position within the specialty biotech market segment.
Risks
- The Relative Strength Index (RSI) suggests that despite strong past performance, Insmed’s stock may be entering an oversold phase, indicating potential market volatility.
- The upcoming earnings report on February 19, 2026, may introduce uncertainty impacting stock valuation and insider trading sentiment.
- The broader biotech sector faces risks from biosimilar and generic competition, which could pressure revenues and growth trajectories, including that of Insmed.