Sure, in the short term, unregulated markets can be manipulated.
But Tether's been around more than seven years, more than enough time for the "smart money" to profit by obliterating them.
You can sell Tether on Coinbase for U.S. Dollar deposits to your bank account.
The fact that Tether maintains its 1:1 peg to the dollar is a signal that maybe all the smart guys who have been confidently predicting its imminent and inevitable failure for the last seven years might be missing something.