Acumen Pharmaceuticals, Inc. (ABOS) — Insider Trading

AI-Powered SEC Filing Analysis

Latest Insider Trading Filed: 2026-03-18

Key Insights

RA Capital Management, L.P. and its related entities hold a significant ownership stake of over 19.7 million shares (around 31%) in Acumen Pharmaceuticals, Inc. (ABOS), making them a major shareholder and influential investor.
The filing shows RA Capital Management, L.P. acquired an additional 6,060,606 shares of ABOS at $3.3 per share, further increasing their position in the company.
The presence of RA Capital Management, L.P. and its principals (Peter Kolchinsky and Rajeev Shah) on the ABOS board of directors suggests they have a strong influence over the company's strategic direction.

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Earlier Insider Trading filings

Filed: 2026-01-23

Insider Derek Meisner, the Chief Legal Officer and Corporate Secretary, has sold over 8,934 shares of Acumen Pharmaceuticals (ABOS) in the past three days, likely to cover tax withholding obligations related to the vesting of restricted stock units.
The sales were executed through Rule 10b5-1 trading plans, indicating the transactions were pre-planned and not necessarily a reflection of Meisner's views on the company's prospects.
The share sales represent only a small portion of Meisner's total beneficial ownership, which remains at 173,999 shares, or approximately 0.5% of the company's outstanding shares.

Filed: 2026-01-23

The reporting person, Eric Siemers, who is the Chief Medical Officer of Acumen Pharmaceuticals, Inc., sold a total of 3,226 shares of the company's common stock on January 21 and 22, 2026 through an automatic 'sell to cover' transaction to satisfy tax withholding obligations.
The shares were sold at weighted average prices of $1.8035 and $1.82, respectively, indicating an orderly sale of shares by the insider.
The reporting person continues to hold a significant stake of 255,371 shares in the company, suggesting he remains committed to the long-term success of Acumen Pharmaceuticals.

Filed: 2026-01-23

Insider Matt Zuga, CFO and Chief Business Officer, sold 4,160 shares of Acumen Pharmaceuticals (ABOS) through an automatic 'sell to cover' transaction to satisfy tax withholding obligations related to vesting of restricted stock units.
The sales were executed at weighted average prices of $1.8072 and $1.86 per share, totaling approximately $7,600.
The reported transactions represent less than 1% of Zuga's total beneficial ownership in ABOS, which remains at 306,611 shares.

Filed: 2026-01-23

The CEO, Daniel Joseph O'Connell, sold 12,035 shares of Acumen Pharmaceuticals, Inc. (ABOS) stock on January 21 and 22, 2026 under a 10b5-1 trading plan.
The sales were to cover tax withholding obligations related to the vesting of restricted stock units, indicating the shares were not sold for discretionary reasons.
The CEO still maintains a substantial position of 881,275 shares, suggesting continued confidence in the company's prospects.

Filed: 2026-01-23

The Chief Operating Officer, Russell Barton, sold a total of 2,777 shares of Acumen Pharmaceuticals, Inc. (ABOS) on January 21-22, 2026 through an automatic 'sell to cover' transaction to satisfy tax withholding obligations on vested restricted stock units.
The shares were sold at weighted average prices of $1.806 and $1.84, respectively, indicating that the insider transaction was likely routine and not a reflection of a significant change in the company's outlook.
The reporting person still holds a substantial 205,092 shares in the company, suggesting they remain confident in Acumen Pharmaceuticals' long-term prospects.

Filed: 2026-01-21

The reporting person, Derek M. Meisner, acquired 99,133 shares of the issuer's common stock in the form of restricted stock units (RSUs), increasing his total beneficial ownership to 182,933 shares.
Meisner also received a grant of 148,700 stock options with a strike price of $1.89, vesting over 4 years, further aligning his interests with the company's long-term performance.
The timing of these grants suggests the company is focused on retaining and incentivizing key leadership, which could be positive for investors.

Filed: 2026-01-21

The CEO, Daniel Joseph O'Connell, acquired a significant number of 299,800 restricted stock units (RSUs) in the company, indicating his confidence in the company's future performance.
In addition, the CEO was granted 450,000 stock options with an exercise price of $1.86, further aligning his interests with those of the shareholders.
The vesting schedules for both the RSUs and stock options suggest a long-term commitment from the CEO to the company's growth and development.

Filed: 2026-01-21

Matt Zuga, the CFO and Chief Business Officer, acquired 99,133 restricted stock units (RSUs) for the company, indicating his confidence in the company's future prospects.
Zuga also received an employee stock option to purchase 148,700 shares of Acumen Pharmaceuticals' common stock, further aligning his interests with those of shareholders.
The vesting schedules for both the RSUs and stock options suggest Zuga is committed to the long-term success of the company.

Filed: 2026-01-21

Eric Siemers, the Chief Medical Officer of Acumen Pharmaceuticals, Inc. (ABOS), acquired 99,133 shares of the company's common stock through a restricted stock unit (RSU) award on January 16, 2026.
Siemers also received an option to purchase an additional 148,700 shares of ABOS common stock, which will vest over the next four years, indicating his long-term commitment to the company.
The insider buying activity suggests that Siemers is bullish on the company's prospects and believes in the future potential of ABOS.

Filed: 2026-01-21

The reporting person, Russell Barton, acquired 84,600 shares of Acumen Pharmaceuticals (ABOS) common stock through a restricted stock unit (RSU) award, increasing his direct ownership to 207,869 shares.
Barton also received a stock option grant of 126,900 shares, vesting over 4 years, further aligning his interests with the company.
The equity awards suggest Barton, as Chief Operating Officer, is viewed as a key leader and contributor to Acumen's long-term success.

Filed: 2026-01-21

The reporting person, Amy Schacterle, was granted 84,600 restricted stock units (RSUs) and 126,900 stock options, indicating potential insider confidence in the company's future performance.
The RSUs will vest in three equal annual installments, and the stock options will vest over four years, suggesting a long-term commitment from the reporting person.
The reporting person's role as Chief Regulatory Officer suggests that this transaction is related to the company's regulatory strategy and compliance, which could be important for the company's future success.

Filed: 2026-01-21

James J. Doherty, the President and CDO of Acumen Pharmaceuticals, Inc., has received a restricted stock unit (RSU) award of 166,867 shares and a stock option grant of 250,300 shares, both with vesting schedules, indicating potential long-term commitment to the company.
The direct ownership of common stock by the reporting person has increased to 220,900 shares, demonstrating continued investment in the company.
The timing of the transactions, occurring in January 2026, suggests potential alignment with the company's strategic initiatives or a response to recent developments.

Filed: 2026-01-12

The reporting person, Matt Zuga, who is the CFO and Chief Business Officer of Acumen Pharmaceuticals, Inc., sold 6,888 shares of the company's common stock at a weighted average price of $1.8166 per share. This transaction was made pursuant to a Rule 10b5-1 trading plan to satisfy tax withholding obligations in connection with the vesting of restricted stock units.
The reporting person's beneficial ownership in Acumen Pharmaceuticals, Inc. decreased from 216,839 shares to 209,951 shares as a result of this transaction.
The sale of shares by an executive officer may indicate their confidence in the company's current valuation or their need to raise cash, which could be a neutral or negative signal to investors, depending on the context.

Filed: 2026-01-12

The reporting person, Russell Barton, sold 3,530 shares of common stock in an automatic 'sell to cover' transaction to satisfy tax withholding obligations related to the vesting of restricted stock units, indicating ongoing equity compensation and insider participation.
The sale was executed at a weighted average price of $1.8588 per share, within a range of $1.80 to $1.95, suggesting the shares were sold in an orderly manner.
The reporting person continues to hold a significant stake of 123,269 shares as the Chief Operating Officer, maintaining a strong alignment with shareholders.

Filed: 2026-01-12

Insider Derek Meisner, the Chief Legal Officer and Corporate Secretary, has been actively selling Acumen Pharmaceuticals (ABOS) shares over the past few days, including an automatic 'sell to cover' transaction to satisfy tax withholding obligations.
Meisner's total shares beneficially owned have decreased from 127,640 to 83,800, representing a 34% reduction in his stake.
The sales were executed pursuant to a pre-established 10b5-1 trading plan, which suggests the transactions were part of a systematic selling strategy rather than ad-hoc selling.

Filed: 2026-01-12

Insider Daniel Joseph O'Connell, the CEO, sold a total of 26,472 shares of Acumen Pharmaceuticals (ABOS) over 3 days, likely to cover tax obligations from vesting of restricted stock units.
The shares were sold at a weighted average price range of $1.72 to $1.84, indicating the CEO is still holding a substantial position of 593,510 shares.
The insider selling appears to be routine, related to tax obligations, and does not necessarily signal any broader concerns about the company's outlook.

Other reports for Acumen Pharmaceuticals, Inc.

Annual Report Current Report

Important Information

AI-generated analysis is for informational purposes only. Always read original SEC filings and consult with qualified professionals before making investment decisions.