This is one that I'm a firm believer in. The idea here of the five-year rule is that you should only put money into the stock market that you won't need to spend, that you know you won't need to spend for at least five years. The reason dovetails with what exactly I said previously.

The stock market is unpredictable, especially in the short term, and I define the short term as anything less than three years. However, if you can keep your money in the S&P 500 for a period of five years, the odds of you earning a positive real return, real meaning after the effects of inflation, are actually very high.

The number is about 80%. So you have an 80% chance, if you can keep your money in the stock market for five years or longer, of earning a positive real return. That to me is an acceptable level of risk to take on, although everybody is different. But if you're going to go for a shorter time period than that, the math is just not nearly