Investing, of course.
And there are few reasons for that,
First of all, unlike gambling, you don't pay an house edge for the site while you invest, and if you do it's a very small amount(considered a free more than an house edge), in gambling u could end up paying even 10% house edge(sports betting) and at the long run you will always find yourself at a lose.
Also, unlike gambling, while investing you can base your decisions on real time news, while in gambling it's a total gamble and not based on anything.
Investing, assuming you’re talking about investing in cryptocurrencies on an exchange and not the usual ponzi scheme spam that floats around all the time. The idea is that at its foundation, the very company that you invest and trade cryptocurrency through wants you to succeed, whereas gambling websites want you to fail.
Every time you make a trade, do a withdrawal, or open up a position, your brokerage gets a bit of commission, and perhaps a percentage of the total fees. The more you invest, and the more money you move around when doing so, the more money they get.
But gambling companies only want you to lose. Think of how often you see them advertising an extremely small house edge. If a companies best selling point is that they’ve made your odds of losing your money to them as low as they can make it while still turning a profit, that’s probably a bad sign.