When setting up a long position with a stop-loss and a target profit level, the trader is basically long volatility above the entry price and short volatility below it (short convexity and skew). In a market drifting down and moving at 40 vol, this strategy has no chance. It is short vol at the wrong spot.  Instead of using stop-losses to reduce risk, we hedge our positions using spreads.  Everything is relative to something else, and we take risks only when we can exploit a liquidity gap.