Invest in crypto currency? Maybe it's a good way if you want to increase your money if it's still lacking in that amount. But like gambling you must be prepared with all the possibilities that exist.
Investing in crypto and that too in best of the coins will help you to retire rich. If not now than in 5 years of time you will become millionaire easily if you invest in good btc and altcoins in coming time. Also ensure that you do invest on every dip.