I used to use Acorns, which would round up dollars and put them into ETF's but I'm pretty conservative in investing and wanted almost guaranteed returns. So far no defaults, but the lowest loan I buy into is B4 with 0 delinquencies in the last two years. As I get a bigger built up stash I might go riskier, but for now I am content.
You're 20 years old.....?? You seem to have had a lot of investment experiences in a short time.