The biggest question mark in Tether's reserves are the 65% of 'cash equivalents' held in unspecified commercial paper.

Depending on the issuer of this debt, these holdings may not be very liquid.

Interesting why no risk of collapse is priced into Tether? Why doesn't it trade for <$1 real USD?

Tether was the original pumper of bitcoin. Its was got this huge rise started. "Where is all this capital coming from for BTC?!!" Well you see it started as a ponzi scheme and then everyone thought some whale knew something they didnt. And so goes how crypto got started.

and $0.972 in other assets, for a total of 100.2% USD assets for their USD liabilities. (see https://wallet.tether.to/transparency)