You might be lucky enough to become rich by betting all your money on one type of investment. Just like you might be lucky enough to win the lottery. But that’s not a strategy for getting rich (at least, not one I’d ever recommend).
One of the worst financial mistakes you can make is putting all your money eggs in one basket. Doing so puts you at too much risk, whether it is being too conservative or too aggressive. Sure, the stock market is on a run and real estate is on an upswing again, but are you prepared for when the tides turn? Because they will. And if you are invested in all fixed-income securities like CDs, bonds and annuities and think you’re safe, inflation should make you think again. Your investment portfolio needs to include a good mix of investments with varied levels of risk and return potential and liquidity (so you can get your money when you need it).