"Then, this year, Tether Holdings started putting out a huge amount of digital coins. There are now 69 billion Tethers in circulation, 48 billion of them issued this year. That means the company supposedly holds a corresponding $69 billion in real money to back the coins—an amount that would make it one of the 50 largest banks in the U.S., if it were a U.S. bank and not an unregulated offshore company."
A Tether crash would take down a lot of stuff.
Tether (or a substitute stablecoin) is currently a requirement for lots of the Wall Street investment in cryptocurrencies. If it turns to poo, lots of that Wall Street investment does too and it creates huge liquidity/ volume issues.