November is typically the best month for stocks. A quirk among mutual funds may explain the weird phenomenon and point to big gains into year's end

• Talk of stock market seasonality tends to pick up towards the end of the year, and for good reason.
• Since 1950, November has been the strongest month of the year for stock market performance.
• A mutual fund quirk could be driving part of the year-end seasonality.

With November's arrival, there's a lot of talk on Wall Street about stock market seasonality towards the end of the year — and for good reason.