The deposit transaction of 1.5 billion USDT from Tether Treasury to MultiSig address indicates that Tether is taking strategic steps to strengthen the protection and management of a large amount of USDT through a multi signature wallet. The purpose may be: 1. Improve fund security and prevent unauthorized operations; 2. Accumulate reserves to meet future redemption demands or market activities; 3. Respond to regulatory pressure, demonstrate transparency and accountability.