The old adage refers to the fact that, historically, the months of May through October are the weakest of the year for the stock market. (Take a look at LPL Financial’s chart going back to 1950.)

“There are a lot of different ways you can look at this,” says Randy Frederick, Charles Schwab’s vice president of trading and derivatives. Indeed, as LPL notes, the past 10 years have actually not been so bad for stocks during the allegedly bumpy period: The S&P 500 posted positive returns eight out of the past 10 years from May through October. Post-election years (of which this is one, of course) also often bode well for stocks in May. And Frederick notes that, measuring the period from Memorial Day to Labor Day, stocks have been up for the past five consecutive years.

Despite some of those more optimistic historical patterns, there’s a widespread idea that share prices might be due for a breather after an incredible recent run. Following a 24% rise in the S&P 500 in the last six months (and a hefty 87% rise in that benchmark index since March’s lows last year), some pullbacks in the coming months would be “perfectly normal and perfectly logical,” LPL’s Ryan Detrick recently told Fortune.

The upshot of all this: Markets over the next few months might make you want to sell—but many experts believe staying the course, and even buying on any dips, is the way to go.

Market ‘euphoria’?

There’s ample concern that markets in general are far overvalued: The S&P 500’s next-12-month price-to-earnings ratio sits at 22, far above the historical average, per FactSet. And worries fester that the economy, spurred on by big stimulus spending, may be starting to overheat, increasing the possibility of higher inflation.

Yet the predominant sentiment on Wall Street of late has been bullish—very bullish. That’s causing those like Detrick to worry that there’s just too much positive sentiment, and that a correction (or at least a short-term selloff) is in the cards. “Everybody knows everything’s great” he says. “So, how much good news is priced in after an 80-plus-percent rally?”

Strategists at Bank of America note that “euphoric sentiment is a key reason for our cautious outlook” as the bank’s “Sell Side Indicator” is hitting 13-year highs, strategists led by Savita Subramanian wrote in a Monday note.

But despite the headiness, some market experts are readying their shopping lists on the belief that, by year’s end, stocks will go higher still.

Buying the dip

Those like Detrick believe that longer-term, strong corporate earnings, a consistently accommodative Federal Reserve, and a reopening economy should provide a supportive backdrop for stocks. Any near-term selloff is “probably going to be an opportunity, honestly, to buy at some lower prices,” says Detrick, who wrote in a note on Friday that “we’d use any weakness as an opportunity to add to positions.”

Indeed, most of the experts who spoke with Fortune see stocks ending the year at least moderately higher than they are now, boosted by a strong 4th quarter.

For Lindsey Bell, chief investment strategist at Ally Invest, “I think it’s a great time for investors to think about rebalancing,” she tells Fortune. Bell believes things will get a bit choppier in the summer months, “which is why you want to rotate into some of the defensive sectors” like healthcare and consumer staples. Charles Schwab’s Frederick also anticipates a near-term selloff (in the 5% to 8% range over the coming weeks or months, he estimates), and suggests taking it slow: “If there’s something that someone has their eye on” in the next few months, buying on the dips “in small amounts” could be a good plan, he suggests to Fortune.

Overall, with so many retail investors still “bulled up” on the markets, “I’m getting the vibe that people don’t really care this year” about the seasonal axiom, says Ally’s Bell. And based on May’s first day of trading, it looks like Bell is right: The S&P 500 and Dow Jones Industrial Average both closed higher on Monday, up 0.3% and 0.7% respectively.

“Nonetheless,” she adds, “it is a historic phenomenon that I expect to remain intact this year—whether people pay attention to it or not.” And with the longer-term prognosis looking pretty good, most investors can probably afford to ignore it.