Stablecoin giant Tether Holdings is hoping to raise up to $20 billion in a private placement that could give the company a monetary value of up to$500 billion, Bloomberg reported on Tuesday, citing two unnamed sources. The valuation would cast the issuer of USDT, the world's largest stablecoin, into the ranks of artificial intelligence developer OpenAI and Elon Musk's space transport company SpaceX, which received similar valuations. El Salvador-based Tether is aiming to raise $15-$20 billion for an app ...