But I don't understand how you make money on SELL.
For example, let's say I believe BTC will go down. So I BUY BTC. And then I wait for it to go down to go up and then SELL.
Don't I lose money?
That's how you will work buy when the price is low and sell when the price is high.
Fixing the above for you.
I think you need to search what is DCA way of buying Bitcoin.
But this isn't a quick scheme you need to wait a perfect time to sell because the DCA method is designed for long-term investment purposes. It allows you to participate in the potential growth of Bitcoin while avoiding the impact of short-term price fluctuations.