If it was a stop limit, you may have the case where it reached the stop price (.625) but only once. Since it was a "stop limit" and not a "stop loss", your order basically became a limit sell order at .625. Since it never came back to this value, it was never sold. If you had a stop loss, then it would sell for any price below .625. So, probably your execution would be lower than this value, but it would have sold.