Would you say there's a minimum amount? Thought it was quite clear in the courts that it was at least 90% fiat backing with anything else being hard too account for which I'm guessing is doublespeak for "it's ours and you can't touch it".
Virtually all of the people who actually hold tether are exchanges, mostly in the US. Everyday people are rarely exposing themselves to risk here.
Just for comparison, the reserve ratio required by US banks is now effectively 0%.
https://www.federalreserve.gov/monetarypolicy/reservereq.htm