Cooper Turley first started investing in cryptocurrency four years ago.

Bitcoin, currently the largest crypto by market value, was trading at over $2,000 at the time, according to CoinMarketCap. Ether, which is powered by the Ethereum blockchain and is the second largest crypto by market value, was trading at a few hundred dollars. Turley bought both.

Now, Turley tells CNBC Make It, those early investments have made him a millionaire, growing to be worth seven figures, with 90% of that generated in the last two years. (CNBC could not independently confirm documents detailing the transactions and current value of Turley’s crypto holdings.)

“I definitely don’t feel like I’ve ‘made it’ by any stretch — there are far more people who are far better off than me in crypto. But I do feel really thankful,” says Turley, 25.

Though Turley declined to disclose exactly how much he initially invested, “it was not a lot at all,” he says. “At that point, I was still in college, working some ad hoc jobs. I was just putting a couple hundred dollars in, here and there.”

‘I fell down this rabbit hole’

Turley says he first invested in Ethereum while studying music business at the University of Colorado Denver in 2017.

He learned that the Ethereum blockchain has the potential to change the music industry and help artists take more control over their own music — for instance, smart contracts on the blockchain could do