You'll have to correct your friend because having all your investments in one basket is wrong due to alot of things that can happen to that investment and you lose everything. Always diversify into investment that are legit and not scams by doing thorough research before putting in your money because it would had been better to lose all your money your trying different investment than when you out them all in one scam investments. Diversifying helps you in time when you're in need of urgent cash then your investments come to save you. But when they're all in one, you might be at lose but won't be getting any choices here because you can't sell at a lose.