The winning strategy for us who do not want to gamble but save some extra for our retirement is to stop looking at the daily values, and invest the same amount monthly to a low cost ETF, such as VUAA.

Now, the S&P 500 has been coming up about seven percent yearly if you look into it for a longer period of time. Repeating the monthly investment until you retire is a good way to get enough to retire comfortably.