“Buying high and selling low” is far and away the biggest mistake investors make.
Investors are plagued by human psychology. As a species, we learned to survive by paying close attention to recent events and assuming those events will be repeated. This strategy worked well for hunter-gatherers who quickly learned to flee from rustling bushes and to avoid eating white berries.
Unfortunately, in investing scenarios, this psychology leads many of us to buy stocks after share prices jump based on the assumption they will rise again. Similarly, we want to sell stocks after a price drop, thinking they will continue falling. This behavior leads to markets going on long runs either up or down based strictly on investor psychology. To make matters worse, many professional short-term traders are aware of this and jump on these trends, extending the movements even farther.
How does an investor cope with markets plagued with irrational decision-makers? Any trend that can’t continue forever won’t. Eventually, markets revert to their long-term fundamental values. The key is to work with your advisor and examine every investment’s long-term potential. Then, have the courage to take some profits when stocks are rising and buy when the market is falling. This might cause some heartburn because it’s counter to our instincts, but that’s okay. You’re human after all.