USDT, formally known as “Realcoin,” is issued by a company in Hong Kong called Tether. Realcoin was issued in 2014 as a second layer token on Bitcoin’s blockchain and now, Tether is second layer to Bitcoin, Ethereum, EOS, Tron, Algorand, Bitcoin Cash and OMG. Tether (USDT) is the largest stablecoin according to market capitalization. The primary purpose of Tether is to keep its value steady at $1. The company achieves this by allocating in its reserve the same amount of dollars as USDT coins they produce.