What a spike in T-bill yields says about default risk

CNBC reports:

Yields on one-month Treasury bills continue to head higher this week, a sign that investors are getting increasingly nervous about the prospect of the U.S. government defaulting on its debt obligations.

The U.S. could start to miss payments on its debt if Congress and the White House fail to reach a deal to lift the $16.7 trillion limit on government borrowing by October 17.