A stop-loss helps to mitigate the risk by reducing losses when the crypto market falls. There are several different types of stop-loss: percentage, volatility, time stops; full, partial, and trailing stop loss. Each has its own pros and cons. There is no unique strategy and the choice of stop-loss completely depends on a trader. Anyway, this tool is useful and should be used whenever you open position. So far, not all crypto exchanges provide this feature. I read about the forthcoming opening of a new platform Cex Broker (https://twitter.com/cex_io/status/1102941285143506945 or https://cexbro.com/) that supports a stop loss, margin trading and other advanced features. A stop loss is a tool for risk managing, and I assume it saved many traders from a complete crash.