You can easily adjust for weekends, but since you also want to skip holidays then somewhere at the start of your program you will need to hardcode all the holidays that you know of (the days which do not have your Stock data). Some holidays are always on the same day like Christmas for example, but others like Easter need to be calculated.
If you have a way to test for a holiday by checking the database (you said holiday data does not exist in the database, so this could be one condition to test before adding a day) ...then you can skip that day.
Either way you will need to add more than one to your LoopDate to skip those days you don't want, as John Oliver suggested.
