$USDC $USDC $FDUSD USDC and USDT are the two most popular stablecoins, pegged to the USD at a 1:1 ratio. USDC (USD Coin) is issued by Circle, which is more transparent with regular audit reports, with backing assets primarily in cash and U.S. government bonds. USDT (Tether) is issued by Tether Limited, which has a larger trading volume but has been embroiled in controversies regarding transparency and asset reserves. Both are widely used in cryptocurrency trading, but USDC is often rated higher for reliability and transparency.