Mark Walter turned Delaware Life, a standard insurer he acquired 13 years ago, into a major private-credit lender. Analysis shows private-credit deals now make up about 45% of its nearly $42 billion debt investments, a sharp rise from 9% in 2014. Two of the insurer's three largest investments are to affiliated Walter companies, with the other tied to his financial firm, Guggenheim Partners.

This shift reflects a Wall Street trend of life insurers funneling policy premiums into high-interest private loans. The difference between loan interest rates and policyholder yields generates significant profits. Walter's insurance empire faces a federal investigation after reclassifying about $20 billion of investments as affiliated transactions.

Regulations require insurers to buy investment-grade debt, but Walter's firms create complex investments that receive high ratings while paying high interest. Many loans carry credit ratings from Egan-Jones Ratings. About 80% of identified loans are rated at or below BBB, the lowest investment grade category.

Delaware Life's largest investment is a $296 million debt to a Guggenheim-managed fund. Guggenheim used some of that money to finance a $450 million loan to dating app maker Bumble, compounding fees made off the insurer's money.