People predicting stock market declines have thus far been predicting something which declines and then eventually bounces back.
This will not happen to Tether - when it blows up, like Mt. Gox, or a host of other crypto scams have - it will not be coming back.
As someone else here said, markets can remain irrational longer than you or I can remain solvent. Bernie Madoff's Ponzi scheme collapsed in 2008 not due to Harry Markopolos talking to the SEC in 2000 (or after) - it collapsed because everyone started withdrawing their money at once, and then the whole house of cards collapsed.