How to deal with stop losses outside of market hours?

I've been using the SMA to enter and exit my positions. The issue is that a lot of the fun happens before the market opens, so by the time my orders execute at market open it's basically too late to make it work. Especially for stop losses - if I place a stop loss 2% below the SMA and the stock dips 5% before market hours, then it's too late. I know the order is not guaranteed to execute exactly at the 2% below, but I would like to stop it from dipping lower. How do you all deal with such cases outside of market hours?