What is considered a good ROI?

Anyone who can consistently make 10% a month could compound a $50,000 starting balance in to over a million dollars in 32 months maximum if they didn’t drop below the 10% profit in any one month. Is that realistic? Probably not. Let’s drop to 5% minimum every month. That would take 62 months to get to a million. Sounds great, but there will undoubtedly be negative months I am almost positive.