The first rule to know about stocks is that you should invest in stocks for at least 15 years. You should invest money in stocks that you will not need in the next 15 years. This is due to the fact that in a short period of time, for example, in 3-5 years, shares can show a loss, but for long periods of time, the stock market, as a rule, always grows. By investing in stocks for just a few years, there is a high chance that you may lose some of the money invested, so consider stocks only as a long-term investment for at least 15 years.