HSR Waiting Period Expires for Biogen Acquisition of Apellis
APLS has more than doubled off its 52-week low of $16.1.
Summary
Apellis Pharmaceuticals announced the expiration of the HSR waiting period, clearing a major regulatory hurdle for its acquisition by Biogen.
Key Events · M&A and Partnerships · APLS
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HSR Waiting Period Expired
The required waiting period under the Hart-Scott-Rodino (HSR) Act for the tender offer and merger with Biogen expired at 11:59 p.m., Eastern Time on May 11, 2026.
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Key Regulatory Condition Met
This expiration satisfies a critical regulatory condition for the acquisition, moving the transaction closer to completion by removing a significant antitrust hurdle.
Analysis · APLS · Life Sciences
This amendment confirms that the Hart-Scott-Rodino (HSR) Act waiting period for Biogen's acquisition of Apellis Pharmaceuticals has expired. This satisfies a key regulatory condition for the tender offer and merger, significantly advancing the deal towards completion. The expiration of this waiting period removes a major regulatory hurdle, making the acquisition more certain.
How filings like this one have moved
In the 30 days to Aug 26, 2026, 43.5% of the 1024 measured filings Wiseek scored 9 moved their stock by 5% or more by the next session's close. The median move was -0.12%. 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, APLS was trading at $41.04 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $5.3B. The 52-week trading range was $16.10 to $41.14. This filing was assessed with positive market sentiment and an importance score of 9 out of 10.