Most of the time, one stock's single-digit percentage rise or fall in any given month isn't all that interesting. It happens. Stocks are supposed to ebb and flow.

That's what makes last month's small sell-offs from Apple (AAPL 1.30%), Visa (V 1.22%), and Walt Disney (DIS 0.55%) so unremarkable. While these Dow components lost more ground than any of their Dow counterparts, the worst-performing of these -- Apple -- still only fell 5% in May. It remains the king of consumer tech, and plenty of investors are using the pullback as a buying opportunity.

Before you follow suit, however, take a step back and look at the bigger dynamic. The Dow's three biggest losers in May are not only the names most likely to benefit from a post-pandemic reopening, they're also the same very names that have led the Dow Jones Industrial Average (^DJI 0.62%) higher over the course of the past several months. To see these leaders suddenly turn into laggards is a hint of a big shift in investor sentiment that just might work against the broad market for a while.

From leaders to laggards

Although the Dow advanced 2% last month, Apple, Visa, and Disney shares fell 5%, 4%, and 3%, respectively, in May, holding the Dow Jones Industrial Average back more than any of the other names that make up the index. But all the figures are fairly modest.

Man stopping a red arrow chart from falling any farther.

Image source: Getty Images.

Read between the lines, though: Something's changed.

Sure, you could argue that Disney's disappointing subscriber growth for its Disney+ streaming service is the culprit for its weakness. The thing is, Disney shares were already peeling back from their March peak when that news hit last month. Visa's rally lasted all the way through its late-April peak at a record high of $237.50 before it began to weaken, largely in response to last quarter's results. While hardly horrifying, the 2% slide of its top and bottom lines loosely suggests whatever reopening benefit the payment company is going to reap has already been mostly reaped. And as for Apple, its all-time peak came all the way back in January. While its fiscal second-quarter numbers posted at the end of April were nothing less than stellar (sales were up 54% year over year to reach a new Q2 record), the market chose to see the proverbial glass as half empty rather than half full. The company also says it's feeling the impact of the chip shortage.

Yet none of these are the sorts of challenges that would have dragged these stocks lower in the recent past. To see three of the Dow's very best performers start to lag simultaneously is telling, not so much about these three companies, but about investors' broad perceptions of the market's current health.

Right on cue

And curiously, these clues are taking shape exactly when you'd expect them to.

While most long-term investors shouldn't be timing their entries and exits to correspond with what looks like the market's lows and highs, it would be naive to ignore how the major indexes entered this year's "sell in May" period well above where they'd normally be. As of the end of April the S&P 500 was up 11.5% from the end of 2020, when it would normally be up on the order of 3.4%. Last month's weakness filled in some of that gap, but most of it remains unfilled.

The S&P 500 is well ahead of where it would normally be at this point in the year.

Data source: Thomson Reuters. Chart by author.

And lest you think this year's bullish start is merely the back end of last year's rebound from a strong sell-off when the coronavirus pandemic began in the United States, it isn't.

Although the S&P 500 was down as much as 35% in early 2020, it ended that year 16% higher than where it started it. This year's big gains simply move the market deeper into overbought territory, further ripening it for the sort of profit taking we're seeing take shape now. With influential names like Apple and Disney setting the tone, other stocks may soon mirror their weakness.

A simple answer

So to answer the question, no, the Dow's May laggards aren't buys here -- at least not yet.

That doesn't necessarily make them sells if you currently own them, particularly if there are tax consequences of selling. All three are still fine companies with a bright future. The red flags waving here are simply pointing to weakness mostly stemming from profit taking, but don't signal the onset of a full-blown bear market.