TON on DEX StonFi and Dedast collapsed because they pulled liquidity. The price on the coinmarket dropped to $0.3 
Has anyone been able to swap $0.3 there and drop it on the exchange? Write in the comments 

Such situations on coins are not the first time, in general, it means that someone simply collapsed the rate on DEX exchanges
Or did it on purpose to take away your liquidity. The arbitrators will level the price anyway, and the centralized exchanges will be in the negative, where these tokens will then be poured