Get ready for March Madness [spike] on Wall Street

Bet on the markets, not the brackets

The NCAA basketball tournament is nearly here, and while we don't know who is going to win the title, we can predict one thing. The stock market is probably going to do better than your bracket. Based on data from the past 10 years, almost every major stock has seen a positive return during the annual tournament.

According to some estimates, there could be upwards of $9 billion bet on this year's tournament, through 70 million brackets created. The vast majority of people are going to lose out in their brackets, and they most likely would have returned a profit instead if they had traded stocks.

The breakdown comes from market data firm Kensho. Simply put, every single stock in the Dow Jones average has had a positive return in the past 10 years during the time frame of March 17 through April 6, the dates of this year's tournament. Without exception, equities have gone up on average.

Expanding the data further, consider the membership of the S&P 500. Going back 10 years, we also found a massive proportion of positive stocks. In the table below, we've only included companies that have been around for the past 10 years (excluding examples like Facebook, post-bailout General Motors and Chipotle Mexican Grill, which don't have a full decade of data).

Of the 445 stocks included in the analysis, a meager 12 of them have experienced a negative average return—meaning that over 97 percent of them were up.

Leading the way consistently has been video game retailer Gamestop, averaging almost a 13 percent gain during each year's tournament. It's been up in nine of the 10 past years, showing that it has some consistency during this part of the calendar.

As the stock market has seen a very rapid decline in March, it will be harder for the end-of-March data to show a positive return. Conversely, a possible short-term bottom just as the tournament starts might mean that in three weeks, this year's tournament will see another set of gains. And compared to how poorly most of the country's bracket bets will do, stocks will almost surely be the smarter trade.

One analyst suggested two reasons for the seasonal stock gains. First, quarter-end means that fund managers are pushing up stocks to mark the price in their portfolios. Second, tax refund checks are being mailed out, giving people an impetus to reinvest.

DISCLOSURE: CNBC's parent NBCUniversal is a minority investor in Kensho.