By CCN.com: The Dow’s bull run is one for the history books, but it could all come crashing down next month. Stocks have only generated the types of returns that they’ve delivered year-to-date a handful of times since the Second World War, as CFRA’s Chief Investment Strategist Sam Stovall points out on CNBC. By 1942, the Dow was trading at less than 100 and stocks were in bull-mode in anticipation of victory.

If history’s any teacher, there’s still more runway for gains throughout April.

“Right now, we are on target to be the fifth best year-to-date through April performance since WWII,” said Stovall.

While the trend may be your friend, it could also come back to bite you as traders gear up for yet another adage: “Sell in May and go away.” Stovall suggested that stocks are showing signs of being “overbought” anyway. In that case, the Dow could be stuck in the doldrums for months.

“As we move into the summer, I probably would not be surprised if we see a little bit of retrenching in the markets,” said Stovall, adding: “There is a chance that…the market could end up attempting to digest some of the gains it’s already experienced.”

If history is set to repeat itself, May is going to be a rocky month, with the pattern suggesting that stocks only managed to advance “0.01% of the time” in the month historically. After that, it will be nothing more than fractional gains from May through October.

With stocks barreling toward record highs, investors are trying to capture whatever gains they can ahead of the summer doldrums. State Street’s Matt Bartolini suggests that it’s risk-on with an asterisk. He told the Wall Street Journal:

“People see the market gains, and there’s a little FOMO: fear of missing out. But rather than going in with both feet, they’re kind of dipping their toes in.”

‘Melt-Up’ Phenomenon

Stovall isn’t the only one who feels this way. Leave it to Larry Fink, who is at the helm of BlackRock, the largest asset manager in the world, to warn about a “melt up” in the stock market. He expects that there’s smart money left to come off the sidelines and into stocks, which incidentally will bolster the Dow even further. The party won’t last, however, and investors looking to follow the leader could be left holding the bag when the rally runs dry.

The Dow has been meandering between positive and negative territory today and most recently is trading higher.