I do want to point out that this is mostly only possible because of the insane bubble going on the last 5 months. During normal periods of time the returns are not at all comparable to my salary, so definitely still work hard as a med student and try to get into a good field to make that cheddar $$$.  But I do regret not investing in the Ethereum ICO I had planned on because I got so busy during residency.  So just keep an eye out on things you really think are innovative.  If you're budgeting $10K maybe put 3.3K into 3 different currencies but be patient and wait for the right ones.

The only 3 I've ever been willing to put money into have been BTC, Ethereum @ ICO and Qtum @ ICO and frankly Qtum is mostly on a crazy speculative bubble right now since the testnet isn't even live but the token already went from 30 cents to $8, so it's likely crazy overvalued at the moment.  If you want the crazy returns that can help you pay off some of those loans I would just hold out for a new currency instead of buying into any existing ones, especially given the valuations now.

Anyways I think the nice thing about knowing that you're going to be a physician is that you can be slightly more risk taking than most people.  But again, don't go too crazy, it can all go south and I don't want to hear about some doctor committing suicide over cryptocurrency losses, lol.