RA Capital Sells 1.49M Septerna Shares at $42.50 in Block Trades
SEPN has more than doubled off its 52-week low of $10.74.
Summary
RA Capital sold 1.49 million Septerna shares at $42.50 each, cutting its stake to 11.8% from 13.4%.
Key Events · Ownership and Investor Activity · SEPN
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Block Sales by RA Capital
On August 12, 2026, RA Capital Healthcare Fund and Nexus Fund III each sold 746,500 shares at $42.50 per share, totaling 1,493,000 shares for approximately $63.5 million.
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Ownership Stake Reduced
RA Capital's beneficial ownership decreased from 13.4% to 11.8% of Septerna's 46,676,947 outstanding shares.
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Option Vesting
RA Capital reported vesting of stock options for 16,623 shares on June 17, 2026 and 835 shares on July 28, 2026, with exercise prices of $10.24 and $6.81 respectively.
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Prior Disclosure Context
The Nexus Fund III sale was previously disclosed via Form 144 on August 12, 2026; the Fund's block sale is newly reported in this 13D/A.
Analysis · SEPN · Life Sciences
A significant distribution by a major institutional holder occurred on August 12, 2026, when RA Capital entities sold a combined 1,493,000 shares of Septerna at $42.50 per share, generating approximately $63.5 million in proceeds. The sale reduces RA Capital's beneficial ownership from 13.4% to 11.8% of outstanding shares. While the Nexus Fund III portion was previously disclosed via Form 144, the Fund's block sale is newly reported.
How filings like this one have moved
In the 30 days to Sep 15, 2026, 29.9% of the 1678 measured filings Wiseek scored 7 moved their stock by 5% or more by the next session's close. The median move was -0.25%. These are measured outcomes after filings of this importance, not a forecast for this one.
Measured one observation per ticker per day, after exclusions. Current figures: Filing Impact Tracker · open dataset
At the time of this filing, SEPN was trading at $45.39 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $2.1B. The 52-week trading range was $10.74 to $51.10. This filing was assessed with negative market sentiment and an importance score of 7 out of 10.