An obscure cryptocurrency project that had $18 billion in investor funds as recently as last week is teetering on the brink of collapse.TerraUSD is an algorithmic stablecoin, meant to be pegged 1-1 to the US Dollar. The peg broke this week, and the coin is now trading for around 40 cents.TerraUSD was the third-largest stablecoin with roughly 18 billion in assets at its peak. Some investors are also worried that Tether, USD Coin, and Binance Coin could see similar runs.What the panic means for Bitcoin and stocks.