Following recent troubles of Terra USD stable coin, which fell as much as 70% in few hours, world's largest stable coin Tether briefly decoupled from its one-to-one US dollar peg and, as of May 12th 2022, reached a low of 95 cents per dollar.

Before arrival of alternative crypto tokens that do the same thing as Tether (Binance USD, Terra USD, Dai, USD Coin, True USD and others), Tether was considered to be the "lifeblood" of altcoin exchanges, as many non-banked exchanges used it as replacement of FIAT money. Many altcoins traded there saw most of their market volume execute in Tether.

Today Tether is less systemically important but still maintains its status as largest tokenized version of US dollar, and complete collapse would likely still crash crypo markets and have spillover effects in traditional finance, as Tether has reached almost "too big to fail" status with over 80 billion USD in deposits.

As luck would have it, this decoupling episode was brief and seems to be over at the time of writing this. In space of 7 hours Tether was trading back up at 0.997 USD and whoever was emboldened by relative success of Terra USD attack, failed to cause large scale disaster in Tether.

Whether it or they failed to achieve their goals is unclear, as this episode caused sharp decline in major cryptocurrencies. It could be that whoever was behind this, entered short positions in most vulnerable altcoins, and made large profits.

It is also likely there was no organized attack at all, and this excessive selling of Tether and subsequent decoupling was merely result of social media induced panic.