Why invest if there is a risk of losing money? Because “risk” and “reward” are two sides of the same coin. If you choose not to risk your money, you should reasonably expect a lower return. Conversely, if you accept greater risk, you would expect the potential for proportionately greater rewards.
The longer your time horizon, the more likely you are able to financially withstand an investment's poor short-term performance because there is still the potential for achieving a higher average return over time.