Exiting Insmed (INSM) Following Disappointing Key Drug Uptake

Exiting Insmed (INSM) Following Disappointing Key Drug Uptake

Thu, September 10, 2026 at 2:52 PM GMT+3 3 min read

• INSM +1.67%

American Century Investments, an investment management company, released its second-quarter 2026 investor letter for the "American Century Investments Focused Dynamic Growth Fund". The letter can be downloaded here. U.S. stocks advanced sharply with double-digit quarterly gains largely due to robust earnings, resilient economic data, and momentum in AI-related stocks. However, there was a slight pullback in June as momentum waned and investors anticipated potential interest rate hikes by the Federal Reserve. Growth and AI stocks outperformed value stocks, while large-cap companies generally surpassed small- and mid-cap stocks. Underperformance was noted in healthcare and communication services, while industrials, particularly in aerospace and defense, contributed positively to performance. The fund's investor class returned 16.38%, slightly below the Russell 1000 Growth Index's 16.74%. The investment approach focuses on bottom-up financial analysis to identify large-cap companies with long-term earnings growth potential, while aiming to mitigate non-financial risks. Please review the Fund's top five holdings to gain insights into its key selections for 2026.

In its second-quarter 2026 investor letter, American Century Investments Focused Dynamic Growth Fund highlighted Insmed Incorporated (NASDAQ:INSM). The Fund exited its position in Insmed Incorporated (NASDAQ:INSM), a clinical-stage biotechnology company that develops and commercializes therapies for patients with serious and rare diseases, during the quarter. On September 09, 2026, Insmed Incorporated (NASDAQ:INSM) closed at $128.80 per share. Over the past month, Insmed Incorporated (NASDAQ:INSM) returned 1.96%, but its shares are down 11.65% over the past year. Insmed Incorporated (NASDAQ:INSM) has a market capitalization of $28.13 billion, and its stock has traded within a 52-week range of $90.39 and $212.75.

American Century Investments Focused Dynamic Growth Fund stated the following regarding Insmed Incorporated (NASDAQ:INSM) in its Q2 2026 investor letter:

"Insmed Incorporated (NASDAQ:INSM). We sold our position in this clinical-stage biotechnology company in favor of stocks that we think are more attractive. Unfortunately, we believe the company's underlying performance and uptake of its key drug, Brinsupri, have been disappointing, despite it serving a large, unmet medical need."

Insmed Incorporated (NASDAQ:INSM) is not on our list of the 40 Most Popular Stocks Among Hedge Funds. According to our database, 88 hedge fund portfolios held Insmed Incorporated (NASDAQ:INSM) at the end of the second quarter, compared to 67 in the previous quarter. While we acknowledge the potential of Insmed Incorporated (NASDAQ:INSM) as an investment, we believe certain AI stocks offer greater upside potential and carry less downside risk. If you're looking for an extremely undervalued AI stock that also stands to benefit significantly from Trump-era tariffs and the onshoring trend, see our free report on the best short-term AI stock.

In another article, we discussed Insmed Incorporated (NASDAQ:INSM) and shared Artisan Global Opportunities Strategy's views on the company. In addition, please check out our hedge fund investor letters Q2 2026 page for more investor letters from hedge funds and other leading investors.

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This article is originally published at Insider Monkey.