I just set a trailing stop loss on some stock I had before the correction we are going through right now for 10% below the bidding price. This means at $39.70, the stop loss should have been triggered and turned into a market order. However, the stocks actually sold at around $41. Is this due to the delay between when the market order was set and when the stock was actually sold? Is it common to be so different? I thought setting a trailing stop for the bidding price meant that when triggered, there was already someone willing to buy the stock at that price so it should be sold at that number (or very close to it at the very least). My guess is setting it for the asking price will likely cause the stock to be sold at a lower price than you specified because the actual price people are willing to buy the stock for will likely be lower than the asking price. Is this correct?