Blanket Bond

No, a blanket bond is not a type of bond, financial or deep. Rather, it’s a type of insurance.

Blanket bond [insurance] is bought by brokerages, investment bankers, and other businesses in the money game to protect themselves against their maybe-sketchy employees.

For instance, if someone at Wells Fargo forged a check (they’ve done much worse), then Wells Fargo wouldn’t take the fall for the financial dishonesty. The employee would.