# Plymouth Rock Group of Companies

Plymouth Rock Group of Companies is an Insurance based in Boston, United States.

## Overview

- **Organization type:** Insurance
- **Headquarters:** Boston, United States
- **Region:** North America
- **Address:** Boston, MA, United States
- **Founded:** 1982
- **Assets under management:** Undisclosed
- **Website:** plymouthrock.com
- **LinkedIn:** https://www.linkedin.com/company/plymouth-rock-assurance

## Regulatory record

- **Reports private funds:** No

## About

Plymouth Rock Group of Companies is a US-based insurance company headquartered in Boston. It oversees approximately $4.2 billion in assets across 15 funds, primarily focused on North America.

## Sectors

- InsurTech

## Offices

- Woodbridge, NJ

## People

- James M. Stone — Founder, Chairman, and CEO
- Hal Belodoff — President and COO

## Questions

### How is Plymouth Rock structured differently from other large personal-lines carriers?

Each Plymouth Rock carrier — there are separate entities in Massachusetts, Connecticut, New Hampshire, New Jersey, New York, and Pennsylvania — maintains its own rate filings, agency relationships, and underwriting guidelines. A centralized technology and actuarial services layer in Boston supports them, but underwriting decisions happen at the state-carrier level. This is distinct from the single-entity structure used by most national auto insurers.

### Who are the long-term equity partners of Plymouth Rock?

Central Securities Corporation, a publicly listed closed-end fund chaired long-term by Wilmot H. Kidd, holds approximately 23% of The Plymouth Rock Company and has been invested since the firm's founding in 1982. Kidd serves on Plymouth Rock's board, making this one of the longest-standing insurance equity partnerships in the US property-casualty sector.

### What connection does James Stone have to insurance regulation?

Before founding Plymouth Rock, Stone served as Massachusetts Insurance Commissioner, where he pushed for competitive-rating reform. He is also a PhD economist, former Fulbright scholar, and author of 'One Way for Wall Street,' a book arguing for stricter financial regulation. That regulatory background directly shaped the firm's decentralized compliance architecture.

### Does Plymouth Rock invest its float like a typical Berkshire-style operation?

Unlike a float-investing model, Plymouth Rock's investment portfolio is primarily a conservative fixed-income portfolio held in support of its policyholder surplus, not a vehicle for equity compounding. The group's focus remains underwriting profitability and organic regional expansion rather than investment-leverage strategies.

### Does Plymouth Rock participate in insurtech or direct-to-consumer distribution?

The group distributes mainly through independent agents, but has layered in direct digital quoting and telematics-based products like Road Rewards, launched in 2023. Plymouth Rock Labs, based in Boston, also functions as an internal technology incubator, developing mobile claims tools and pricing models that are then deployed across the regional carriers.

### What is Plymouth Rock's known posture on M&A or portfolio acquisitions?

The group has historically grown organically, entering new states by creating new operating carriers rather than acquiring existing books of business. On rare occasions it has acquired small renewal-rights portfolios from carriers exiting the Northeast, but transformative M&A is not part of its historical playbook.

## Related profiles

- [Plumbers & Steamfitters Local 72](https://altss.com/profile/plumbers-steamfitters-local-72)
- [PMC Pension Trust](https://altss.com/profile/pmc-pension-trust)

---

Last updated: 2026-06-03T20:00:00.000Z

Canonical page: https://altss.com/profile/plymouth-rock-group-of-companies

Maintained by Altss — https://altss.com — methodology: https://altss.com/methodology