Bank of Marin Bancorp CFO David Bonaccorso Reports ESOP Share Allocation and Direct Stock Holdings

CFO's Beneficial Ownership Structure at Bank of Marin

David Bonaccorso, who serves as Executive Vice President and Chief Financial Officer of Bank of Marin Bancorp, disclosed his beneficial ownership in the company through two distinct mechanisms. The filing shows that Bonaccorso holds shares both directly as an individual investor and indirectly through the company's employee stock ownership plan. This dual ownership structure is common among senior financial executives at regional banking institutions and reflects typical compensation and benefit arrangements for officers in the financial services sector.

The disclosure was filed on July 28, 2026, and covers beneficial ownership as of the earliest transaction date of December 31, 2024. The filing tracks changes in Bonaccorso's ownership position arising from ESOP allocations and dividend reinvestment activity occurring during the 2024, 2025, and 2026 periods. This transparency requirement ensures that investors and market participants have visibility into the ownership stakes held by company insiders, which can provide insight into management's alignment with shareholder interests.

Direct Common Stock Holdings by the CFO

According to the filing, Bonaccorso directly owns 17,764 shares of Bank of Marin Bancorp common stock. These shares are held in direct beneficial ownership form, meaning they are registered or otherwise owned by Bonaccorso without intermediaries. Direct share ownership by senior executives is often viewed by investors as a positive indicator of management confidence in the company's prospects and strategic direction.

The filing does not disclose the acquisition dates, purchase prices, or circumstances under which these direct shares were acquired. The shares represent Bonaccorso's personal investment in the company and are subject to applicable securities law restrictions, including any trading windows, blackout periods, or Rule 10b5-1 plan requirements that may apply to insiders at public companies.

ESOP Allocations and Indirect Beneficial Ownership

The filing indicates that Bonaccorso holds 1,622.41 shares indirectly through Bank of Marin Bancorp's employee stock ownership plan. The ESOP is a qualified retirement benefit plan that allows employees to accumulate an ownership stake in the company through employer contributions and investment gains. The 1,622.41 share amount represents accumulated allocations through multiple periods, including contributions for 2024 and 2025.

The explanation section of the filing clarifies that the 1,622.41 ESOP shares include allocations posted to Bonaccorso's account on December 31, 2024 and December 31, 2025, plus additional shares resulting from dividend reinvestment in 2025 and 2026. This structure demonstrates how ESOP accounts accumulate value over time through both new employer allocations and the automatic reinvestment of dividends paid on ESOP holdings. The specific pricing and valuation mechanics of these ESOP shares are not detailed in this disclosure.

Nature of Indirect Ownership Through ESOP

The ESOP represents an indirect form of beneficial ownership, as Bonaccorso does not hold legal title to these shares directly but rather holds a beneficial interest through the plan trust. ESOPs are structured as tax-qualified trusts that hold company stock for the benefit of participating employees. The trustee of the ESOP, and potentially the company's compensation committee or benefits administration team, manage voting and dividend decisions related to ESOP shares according to plan documents and applicable law.

Indirect ownership through an ESOP can offer tax advantages to both employees and the company, as ESOP contributions may be deductible for the employer and can provide employees with a tax-deferred accumulation mechanism. The filing identifies the nature of Bonaccorso's indirect ownership as "ESOP," which clearly distinguishes these holdings from other potential forms of indirect ownership such as family trusts, partnerships, or holding companies.

Timing of ESOP Postings and Dividend Reinvestment Activity

The filing's explanation of responses section provides detail on the timing of ESOP allocations and related activity. Bonaccorso's account received ESOP allocations on December 31, 2024 and December 31, 2025, which aligns with typical year-end benefit plan funding schedules at many employers. These allocations represent employer contributions made under the ESOP's formula and funding arrangements, though the specific contribution amounts or formulas are not disclosed in this filing.

In addition to employer allocations, Bonaccorso's ESOP account benefited from dividend reinvestment during 2025 and 2026. When an ESOP holding pays dividends, those dividend payments are automatically reinvested to purchase additional shares of company stock rather than being distributed in cash to the beneficiary. This reinvestment mechanism compounds the growth of ESOP holdings over time and increases the total share count attributable to the ESOP account, as reflected in the 1,622.41 share figure reported in the current disclosure.

Officer Status and Section 16 Reporting Obligations

The filing confirms that Bonaccorso is an officer of Bank of Marin Bancorp and therefore subject to Section 16 reporting obligations under the Securities Exchange Act of 1934. As an executive vice president and chief financial officer, Bonaccorso is classified as an officer for purposes of federal securities law, which requires him to report changes in beneficial ownership within two business days of the transaction date. This filing serves as Bonaccorso's Form 4 statement documenting his ownership position and any transactions that occurred during the reporting period.

Section 16 officers are also subject to the short-swing profit rule, which prevents officers from capturing profits from purchases and sales of company securities made within a six-month period. The filing does not disclose any derivative securities such as options, warrants, or convertible securities held by Bonaccorso, indicating that his beneficial ownership consists solely of common stock acquired through direct purchase or ESOP allocations.

Aggregate Beneficial Ownership Position

When combined, Bonaccorso's direct and indirect shareholdings total approximately 19,386.41 shares of Bank of Marin Bancorp common stock. This aggregate position reflects the CFO's cumulative economic interest in the company through both personal investment (direct shares) and employee retirement benefit accumulation (ESOP shares). The filing does not disclose what percentage of outstanding Bank of Marin Bancorp shares this position represents, as the company's total outstanding share count is not included in insider filing documents.

The magnitude of Bonaccorso's beneficial ownership may be evaluated by investors as one indicator of management's financial alignment with shareholder interests. Senior executives who hold meaningful stakes in their companies may be viewed as more incentivized to act in ways that enhance shareholder value. However, insider share holdings must be considered alongside the executive's compensation structure, equity awards, and other financial interests when assessing overall alignment.

Signature and Filing Authority

The disclosure was signed on July 28, 2026 by Krissy Meyer, identified as attorney-in-fact for Bonaccorso. An attorney-in-fact is an authorized representative who may execute legal documents and filings on behalf of the principal. The use of an authorized signatory is common in securities law compliance, particularly when executives delegate administrative and filing responsibilities to corporate legal or compliance departments. The signature by Meyer on Bonaccorso's behalf carries the same legal weight and attestation as a direct signature by the reporting person.

The filing includes standard SEC warnings that intentional misstatements or omissions of facts constitute federal criminal violations under 18 U.S.C. § 1001 and 15 U.S.C. § 78ff(a). These provisions underscore the serious legal consequences associated with inaccurate insider ownership disclosures and reinforce the importance of accuracy in Section 16 filings.

Investor Considerations Regarding Insider Ownership Disclosure

Investors monitoring Bank of Marin Bancorp may wish to review insider ownership filings as part of their broader due diligence on the company's management and governance. Insider ownership patterns, when reviewed across multiple executives and over time, can provide insights into management retention, confidence in company performance, and the structure of executive compensation. The filing of a Form 4 by a senior financial officer is routine compliance activity and does not inherently signal positive or negative developments at the company.

The immediate share price impact was not clear from available public information. Insider ownership filings are disclosure documents that provide historical information about beneficial ownership; they do not typically trigger material stock price movements on their own. Investors should consult their financial advisors and conduct comprehensive analysis of the company's financial statements, competitive position, and strategic outlook when making investment decisions.