Safety Insurance Group Affiliates SRB Corporation and Plymouth Rock Company Disclose Sale of 38,835 Shares at $103.08 Each

Coordinated Disclosure by Massachusetts-Based Insurance Affiliates

The filing reveals a joint disclosure by SRB Corporation and The Plymouth Rock Company Incorporated (PRC), both Massachusetts corporations. SRB, a wholly-owned subsidiary of PRC, acts as an investment manager, linking it to the transaction. Both maintain director-level affiliations with Safety Insurance Group Inc., the parent company of the NASDAQ-listed insurer. The joint filing was necessary as the entities may be considered a "group" under Section 13(d)(3) of the Securities Exchange Act of 1934, although each disclaims beneficial ownership of shares held by the other.

SRB explicitly disclaims beneficial ownership of the reported shares, clarifying that its investment management role does not constitute beneficial ownership for Section 16 compliance. PRC similarly disclaims beneficial ownership except to the extent of its pecuniary interest. This distinction is important for investors tracking insider transactions, clarifying the legal and economic relationships between the reporting entities and the shares involved. Such disclaimers are typical in insurance holding company structures where multiple subsidiaries hold shares without asserting individual beneficial ownership.

Extensive Subsidiary Network Controls Majority of Shares

The beneficial ownership is held through a broad network of subsidiaries and affiliated insurance entities. PRC directly owns 4,120 shares of Safety Insurance Group common stock. Additionally, nine PRC subsidiaries collectively hold 755,559 shares, including Plymouth Rock Security Corporation, Plymouth Rock Assurance Corporation, Plymouth Rock Assurance Preferred Corporation, Plymouth Rock Assurance Corporation of New York, Pilgrim Insurance Company, Plymouth Rock Home Assurance Corporation, and three Bunker Hill-branded insurance entities. This reflects the complex corporate structure common among regional insurance holding companies, where subsidiaries operate with separate licenses and capital bases.

Further, Palisades Safety and Insurance Association (PSIA), a New Jersey reciprocal insurance exchange managed by a PRC subsidiary, along with its affiliates, holds an aggregate of 954,060 shares. This includes stakes by High Point Safety and Insurance Company, High Point Property and Casualty Insurance Company, High Point Preferred Insurance Company, Palisades Insurance Company, Twin Lights Insurance Company, and Teachers Auto Insurance Company of New Jersey. The combined post-transaction beneficial ownership across all entities totals 1,713,739 shares. Investors analyzing Safety Insurance Group’s ownership should note the multi-layered subsidiary framework underpinning this substantial stake.

Transaction Details and Pricing

The sale of 38,835 shares occurred on July 24, 2026, at $103.0776 per share, classified as a sale (code "S") under Section 16 reporting rules. The filing was made to the Securities and Exchange Commission on July 27, 2026, within the mandated two-business-day window for insider transactions. There is no indication that the sale was conducted under a Rule 10b5-1 trading plan.

This transaction reduced the combined beneficial ownership from a higher pre-sale level to 1,713,739 shares. Although the filing does not state the total transaction value, multiplying the share count by the price yields an approximate figure useful for investor analysis. The $103.08 price per share offers market context, though the filing contains no commentary on the timing, rationale, or market conditions influencing the sale.

Indirect Ownership and Reporting Structure

The filing classifies the post-transaction beneficial ownership as indirect (denoted "I" in ownership fields) through various subsidiaries and affiliated entities. This is appropriate since shares are held by multiple subordinate entities rather than directly by SRB or PRC individually. Detailed footnotes explain the corporate relationships and subsidiary networks maintaining the ownership position.

The filing’s indentation and footnotes comply with regulatory transparency requirements when insider transactions involve corporate entities. Each subsidiary and affiliate is identified by legal name, incorporation state, and relationship to parent entities. For investors seeking clarity on the economic interest behind the 1.7 million-plus share position, the filing provides a comprehensive roadmap. However, disclaimers of beneficial ownership by some reporting persons may complicate assessments of voting control and economic interest allocation across the subsidiary network.

Director-Level Roles and Regulatory Compliance

Both SRB Corporation and The Plymouth Rock Company Incorporated are designated as directors of Safety Insurance Group Inc., establishing their reporting obligations under Section 16(a) of the Securities Exchange Act of 1934. This classification mandates timely disclosure of ownership changes and ensures insider trading compliance. The filing was certified by Frederick C. Childs on July 27, 2026.

The director-level status subjects these entities to heightened regulatory scrutiny. Future transactions by these reporting persons in Safety Insurance Group shares will require Form 4 filings within two business days. Investors monitoring insider activity should track filings from these affiliates given their substantial holdings and director-level status. The joint filing indicates coordinated compliance and investment activity.

Massachusetts Headquarters and Regional Insurance Operations

Both entities are Massachusetts corporations headquartered at 695 Atlantic Avenue, Boston, reflecting Safety Insurance Group’s New England operational focus. Subsidiaries incorporated in New York and New Jersey indicate a multi-state insurance footprint. Plymouth Rock-branded entities connect this ownership structure to the Plymouth Rock insurance group, historically focused on regional auto and property insurance in the Northeast.

The subsidiary names and jurisdictions reveal a diversified insurance portfolio covering personal auto, property, preferred lines, and reciprocal insurance exchanges. Bunker Hill-branded entities suggest historical acquisitions or separate operating brands. State-specific entities reflect regulatory requirements for licensed insurance operations. This geographic and operational diversity highlights the broad economic interests held by these reporting persons across multiple insurance products and markets.

Pecuniary Interest and Ownership Disclaimers Explained

The filing specifies that PRC disclaims beneficial ownership except to the extent of its pecuniary interest, meaning it claims economic benefits such as dividends but may not assert voting control. SRB’s disclaimer is broader, denying beneficial ownership despite its investment manager role, shielding it from Section 16 definitions while maintaining its management function.

These disclaimers clarify that the economic beneficiary is likely PRC and its subsidiaries rather than SRB. Such arrangements are typical in insurance holding companies, separating management and economic ownership roles.

Form 4 Filing Compliance and Timeline

The filing complies with SEC Form 4 requirements under Section 16 of the Securities Exchange Act of 1934, including all necessary details: reporting persons, transaction date, security description, price, and post-transaction ownership. Signed by Frederick C. Childs on July 27, 2026, it was submitted within the two-business-day deadline following the July 24 transaction. The certification warns that false statements carry federal criminal penalties.

Form 4 provides standardized, transparent insider transaction data for NASDAQ-listed companies. While mandatory, these filings typically do not include commentary on transaction motives or market outlook, leaving interpretation to investors and analysts.

Investment Structure and Ownership Implications

The multi-tier subsidiary structure reflects common insurance company shareholding practices. The 1,713,739 shares held post-transaction represent a significant stake in Safety Insurance Group. Without total outstanding share data, the exact ownership percentage is unknown, but the position size and subsidiary network indicate a major long-term investment by Plymouth Rock-affiliated entities.

The sale of 38,835 shares is a modest reduction relative to the overall holding, likely reflecting routine portfolio management or rebalancing rather than a strategic shift. The transaction’s small scale compared to the total position suggests continued confidence in Safety Insurance Group’s equity value. Investors should assess insider activity within the context of total holdings, transaction frequency, and any company guidance on performance and outlook.