For the past two decades, the S&P 500 has averaged a 0.7% gain during Thanksgiving week and a 0.2% gain in the Wednesday and Friday sessions surrounding the holiday.Here’s what investors should know about trading hours on Turkey Day.

Dating back a century, the week of Thanksgiving and the stretch through New Year’s tends to be positive for stocks.

Here's a bit of history about Thanksgiving and traditions surrounding the holiday. The first Thanksgiving Day "celebration" is said to have taken place in 1621, the History Channel reports. The story,