If the last 100 years are a guide, it is dangerous for investors to assume that either hyper-growth or stagnation/decline will continue indefinitely. In the late 1990s, the S&P 500 averaged a 30% annual return over three consecutive years, but that ended in a bear market. Earlier this decade, home prices rose much faster than normal for several years, but that ended in a housing bust. On the other hand, stock prices have periodically stagnated or declined for a number of years, but bear markets were followed by bull markets. Investors who are swayed by recent events are at a disadvantage compared to those who study—and learn from—the important lessons of history.