HN is the wrong crowd to ask, because they’re behind the curve on a lot of things.
Hop on FinTwit or CryptoTwit.
Derivatives (options/futures) are your best bang:buck. But crypto is where the real speculation is.
Read up on a practical trading book (hypothesis building, backtesting without bias, and risk management via Kelly etc.) and then start testing strategies.
Backtesting you can build yourself with any broker that has an API, but not all are made equal. It’s dead simple.
Look into [redacted]