Investments may lose and gain value at different times. When some investments are down, others may be up. If the values of certain investments have declined significantly, others may not have fallen as much.
If you put all of your money into a single investment, you’d be depending solely on the return of that one investment — for better or worse. Your overall returns would fluctuate right along with any ups and downs of the one investment.
An alternate strategy is to diversify your investments. By spreading your risk, your overall returns wouldn’t reach the lowest lows or the highest highs of any single investment you own. Diversifying your portfolio will help reduce its overall volatility.