haha it really ever happened to my friend, he get 1
BTC in a single day of gambling.
he did very often make a parlay with high odds and at that time I think he's really a lucky day. where he made a parlay bet with the odds @1000 and bet 0.001
BTC, then he won the 1
BTC. he himself did not expect and quite regret that only bet 0.001

Wow!
Your friend must have been so lucky that he won 1
BTC with just a bet of 0.001
BTC.
I have always seen people losing all their money with a bet of all their bankroll even setting the odds to 0.02 or 0.01%, but never heard of something like that, winning with odds 1000.
That's really huge.
You can win some BTC by buying altcoins and selling them. But then you need some luck of course. DO it with an amount you think to be able to spend.