~ 10/15 accident of USDT, which caused a sudden & incredible price increase of bitcoin/eth,
there was no bitcoin price increase! you were mistakenly looking at Tether/Btc and thought that is bitcoin price. instead you should have checked USD/bitcoin to see the price did not change.
at the same time, many investors dumped their USDT & bought bitcoin instead - hence in fact, bitcoin took the responsibility of acting as a stablecoin, which is very interesting.
that is not what happened and that is not what a stablecoin means!
a stable coin is a term that is used for coins that are pegged to another currency so that they are always having the same value as that other currency. for instance Tether (USDT) is supposed to be pegged with USD and 1 USDT should be equal to 1 USD.
there are other stable coins that are pegged to gold, other fiat,...