Could be, and now I'm just spitballing here, but it could be the use of government backed currencies, the heavy degree of government oversight and regulation, and the federally insured deposits.
Barring that you should look at Lawler's article on tether: https://kevinlawler.com/stablecoins
He offers forward contracts if you think he's wrong. He's good for it.
Could be, and now I'm just spitballing here, but it could be the use of government backed currencies, the heavy degree of government oversight and regulation, and the federally insured deposits.