A stop loss is just a trigger point for placing a market order on your behalf. By the time it executed the best price available was 4.988
I assume it was falling fairly fast.
If you are talking about open you can see it gap down here.
Basically a 5.575 stop loss was way too tight unless you were really very confident it was only going up from 5.7
Stop losses need to be way outside the range of play or they will take you out. Even more so on volatile stocks. I would only be confident setting a 5.5 if I had watched it clear min 7.5 and still going north.
In hindsight removing the stop would have been best, or using stop limit with the stop at 5.575 and setting the limit to say 5.4. That would meant you would have got a min of 5.4 when it bounced.
I would run without a stop limit in reality as more often you want out at whatever is the best available. And a stop limit would stuff you if it kept falling down and would never execute.
