Need advice on what to buy

So I have a friend who after years of me trying to convince him of investing/trading crypto finally gave in. The problem is he only wants to risk $20. I told him that you can invest/trade crypto with $20 but you’re not really going to make much unless the market skyrockets.

But I generally want to get y’all’s advice on how one should trade $20 in crypto. What’s a good, high volume, highly volatile crypto coin or project that is under $20 and has the potential to see gains with in the first 6 months to 1 year?