According to Skew Markets, all major stable currencies, including Tether, saw a significant increase in market value in 2019. In terms of market capitalization, USDC became the winner. Tether (USDT) was removed from the study. Following the USDC are TrueUSD, PAX, DAI and GUSD. According to the study, USDC's circulating supply was $342 million, followed by TUSD, with a supply of $232 million.