I currently have logged over 8000 bets with an online casino in the past week and am looking for the best way to log my data going forward. I've looked all around for guidance on how to do taxes for online gambling capital gains, but haven't found anything. I know that I have to pay taxes on the actual winnings themselves, but what about on the capital gains?

Two different approaches I've been considering/wondering if they're accepted by the IRS:
1. If I make 20 quick bets, one per second, losing half and winning half am I required to calculate cap gains for each of them? or
2. Is it possible for me to log my winnings/losings in a particular session and find the capital gain/loss using an average daily price?

I'm really at a loss and all my Google-fu has yielded nothing that's extremely helpful.