That's a bit of a quirky question.

First, many people aren't actually trading fiat $$$, but are trading crypto instead.

So, for example, say you bought some ETH at the IPO at around $4 each, or $500 USD per 2000 ETH, then cashed out last month at 0.15 BTC/ETH...

How do you measure it? By BTC or by USD?

At $3,000/BTC and $400/ETH, that's an old $500 turning into $1.2 million.

Or, that's 1 BTC turning into 300 BTC, which was $900,000.

Currency fluctuations make for difficult conversions sometimes. How you measure it matters. If you're trading for BTC, then it's a different question than for USD/fiat.

That being said, I'm quite certain that many people here have turned a 10x profit or more at least a couple times.