Looking for more evidence of a topsy-turvy, “K-shaped” economy? Check out what’s happening to credit scores.

A report from TransUnion Monday showed the share of people classified as low-risk, super prime borrowers — having credit scores of 781-850, typically — is on the rise, increasing from 37.1% in the third quarter of 2019 to 40.9% in this year’s third quarter. The subprime segment, or riskier consumers with credit scores...