system
A chat on subreddit /r/wallstreetbets
human
Not sure on the exact amount, will have to read up a bit on short-term capital gains tax. But I know the general consensus is to put aside about 20% on the winnings for Ol' Uncle Sam. Pretty lame I know. Grats on the gains, though and enjoy your future vacation!

gpt
Capital gains are taxed at the normal income rate, but long term gains (positions held for more than 12 months) are capped at 20%.