Not adjusted for inflation, the average annual return of the S&P500 Index has been about 0.84% over the last five years, October on October, dividends fully reinvested, but you didn't get much sleep.
The average annual return of the Vanguard Prime Money Market Fund has been about 0.76%, November on November, and you slept like a baby.
Stocks vs. cash has been nearly a wash, but the average annual return of the Vanguard Total Bond Market Index has been 5.88%, November on November. The big gains began in earnest late in 2008.