Siemers Eric 4

What Happened

• Eric Siemers, Chief Medical Officer of Acumen Pharmaceuticals (ABOS), sold a total of 3,226 shares in two open-market transactions to cover tax withholding tied to RSU vesting. On 2026-01-21 he sold 2,331 shares at $1.80 each for $4,204; on 2026-01-22 he sold 895 shares at a weighted average price of $1.82 for $1,629. Total proceeds across both sales were about $5,833. These were sales (routine sell-to-cover), not purchases.

Key Details

• Transaction dates and prices:
  • 2026-01-21: 2,331 shares sold @ $1.80 = $4,204.
  • 2026-01-22: 895 shares sold @ weighted avg $1.82 = $1,629 (individual prices ranged $1.76–$1.87; detailed breakdown available on request).
• Reason/footnotes:
  • Sales were automatic "sell-to-cover" transactions to satisfy tax withholding obligations on RSU vesting under a Rule 10b5-1 trading plan (adopted Sept 3, 2024).
  • Footnote notes the weighted-average pricing range for the 1/22 sales; full per-price breakdown can be provided to the SEC, issuer, or shareholders on request.
• Shares owned after the transactions: Not specified in the supplied filing.
• Filing/timeliness: Form 4 filed 2026-01-23 for transactions on 2026-01-21–22; this appears to be filed within the standard two-business-day window (i.e., timely).

Context

• These sales were automatic sell-to-cover transactions tied to RSU vesting under a pre-established 10b5-1 plan, which is a common, non-discretionary way for insiders to satisfy tax obligations and does not necessarily reflect a change in the insider’s view of the company.