Stop-loss orders can guarantee execution, but price fluctuation and price slippage frequently occur upon execution. Most sell-stop orders are filled at a price below the limit price; the difference depends largely on how fast the price is dropping.

Why did my stop loss not work?

The principal reason stop-loss orders don’t work is because stock prices aren’t serially correlated. This means that what happened yesterday or last month does not necessarily affect what will happen today, tomorrow or next month. Past price movements of stocks do not determine future price movements.

Will a stop loss always execute?

In short, a stop-limit order doesn’t guarantee you will sell, but it does guarantee you’ll get the price you want if you can sell.