Billionaire investor Stanley Druckenmiller's Duquesne Family Office increased its position in Insmed (INSM) by 23.45% during the second quarter of 2026, bringing its total holdings to 1.42 million shares. This disclosure, made in a delayed 13F filing from August 14, reflects trades made by June 30. The move came as Insmed experienced significant momentum from its newly launched drug, BRINSUPRI.
Insmed's revenue has surged, driven by strong sales of BRINSUPRI, a treatment for bronchiectasis. [6] Following the period covered by the filing, the company reported second-quarter revenue growth of 296% year-over-year and raised its full-year revenue guidance for the drug. [2, 5, 9] The increased investment suggests Druckenmiller's growing conviction in the biopharmaceutical company's commercial execution and growth trajectory.