BTC++ (ERC-20) is a BTC synthetic asset generated by PieDAO, which is generated by mortgaging a group of BTC anchor coins (imBTC, pBTC, sBTC and WBTC).
Currently, PieDAO has issued BTC++ and USD++. They are a combination of various BTC (25% imBTC, 25% pBTC, 25% sBTC, 25% WBTC) and USD stablecoins (USDC, TUSD, DAI, sUSD).
You can mortgage the required proportion of BTC-anchored coins on PieDAO to generate corresponding BTC++, thereby reducing the risk of certain BTC-anchored coins suffering from insufficient liquidity or malicious attacks. You can also use Uniswap and other decentralized Trade BTC++ on exchanges.