Is it better to do cryptocurrency trading or stock trading with a small sum of money?

If you have a small sum of money, crypto is definitely better with the low transaction fee and potentially larger upside (iassuming you have a solid strategy that is)

There is no correct answer to which is better.

Whether Forex/stocks/bonds/crypto/commodities/futures/options, anything can be traded but it boils down to your approach and strategy. Your approach may suit a certain asset class and not another, while some approaches may be more versatile.

Dan Zanger and Richard Dennis mentioned "I can trade any chart without knowing what's the underlying asset."

In trading, some argue they can trade solely on technical patterns and i've seen people do it consistently and successfully for years. Others rely more on behavioural finance and fundamentals. There really is many correct ways.

Are you a discretionary or systemetic trader?

I personally trade Crypto, stocks, treasuries, stocks systemetically but my trade plans are very clear before I make the position. I also trade options on stocks via discretionary methods. You can also diversify your strategies and remember to backtest them. There are evidence that diversifying your trading strategy can help improve overall performance.

I use Thinkorswim and Binance​​​