Major cryptocurrencies, including BTC and ETH, saw significant drops, impacting sentiment in the crypto market.The U.S. federal government is investigating Tether, a major stablecoin issuer of USDT.Bitcoin (BTC) dipped to around $65,500 but later rebounded slightly to about $67,085, while Ethereum (ETH) fell to approximately $2,471 from $2,563.The overall cryptocurrency market capitalization decreased by 2.48% to reach $2.28 trillion, but total market volume surged by 43% to $105.01 billion.