Take a look at this. The yield on the 3-month Treasury bill, an instrument the US Government uses for short-term borrowing, has dropped to zero, or a couple of hundredths of a percent away from zero.
Who are the people willing to lend the US Government money for three months and want nothing in return other than a guarantee they’ll get their money back?
The only thing I could think of is if my currency is decreasing in value fast, like Zimbabwe. I can’t think of any reason I’d lend my money to someone for free considering it’s already in US dollars.