Actually, the main risk of value investing

does not lie in "market volatility",

but in "holding time".

The shorter your holding period, the lower the certainty of your returns; the longer your holding period, the higher the certainty of your returns.

The following are the worst average annualized returns of the S&P 500 index since 1928:

1-year period: -44%

5-year period: -13%

10-year period: -2%

20-year period: +2%

30-year period: +8%

Of course, this data basically comes from the Great Depression period of 1929-1933, the worst data in U.S. stock market history.