[dragonwriter]

A stop loss will (assuming anyone is willing to take the other side at any price, since it's a market order) get filled once triggered, but depending on market dynamics with potentially unlimited slippage. Slippage tends to be limited in markets with high liquidity, but as I understand Bitcoin on any existing exchange hasn't consistently shown that behavior.

A stop limit order doesn't have unlimited slippage, but may not get filled at all; there is no foolproof stop order.