Hanover Insurance Group (THG) concentration risks

The company's disclosed concentration profile is geographic, with personal lines premiums concentrated in two states. Approximately 50% of Personal Lines net premiums written is generated in the combined states of Michigan and Massachusetts — a medium-share, structural exposure reflecting where the company has built its agency distribution and policyholder base over time. The structural character is appropriate: the geographic footprint of an established regional insurer is a durable feature of its distribution relationships rather than a single contract that could be terminated abruptly. Within that combined figure, the individual state shares are smaller. Michigan contributed approximately 18.7% of net premiums written — a low-share individual-state exposure. The Massachusetts share, cited in the same filing quote as approximately 8.0%, falls to the same source. Together the two states represent the combined 50% described above. The key risk channel is not counterparty dependency but rather geographic weather and regulatory exposure. Both Michigan and Massachusetts are high-frequency winter weather markets, with meaningful exposure to ice storm, winter wind, and freezing-related homeowner losses. Massachusetts also carries active regulatory oversight of personal auto rate adequacy. A significant loss event concentrated in either state — or a sustained regulatory disallowance of adequate rate increases — would affect a meaningful portion of Personal Lines results. The profile is manageable at these disclosed sizes, but the geographic overlay on two distinct regulatory environments is the primary monitoring consideration.

For the engine’s reasoning on THG’s current verdict — including which dimensions drove the score — see the per-dimension breakdown.

Concentration counts reflect items disclosed in each peer’s most recent 10-K; disclosed-size classification uses TrendMatrix’s internal 10-K extraction taxonomy.