November typically marks the beginning of the growth season in stocks. This is due in large part to pension fund buying patterns, which have produced an average gain of 5 percent from November 1 to January 31 over the last 50 years.

The manager could have made a large sector bet that flopped; he may have made a large commitment to the fund's top 10 holdings, which then underperformed; or the fund may simply have an unskilled manager, someone who can't pick well.

If you're still invested in these funds, you're no longer buying and holding, you're buying and hoping.