The stock market rally in 2021 hasn't been felt equally across the Dow Jones Industrial Average (^DJI -0.93%). Of course, the best performers are in sectors seeing the fastest growth, like banking, consumer tech, and cloud services. Stocks such as Microsoft and American Express have trounced the broader market's 16% surge so far this year.

On the other hand, a few blue chips haven't participated in the rally. And they've been left behind despite improving operating results.

So, let's look at why you might want to buy shares of Procter & Gamble (PG 0.31%), Walmart (WMT -0.10%), and Coca-Cola (KO 0.15%) today.

A father doing dishes with his children.

Image source: Getty Images.

1. Procter & Gamble

Procter & Gamble's latest earnings report showed off the impressive strength of this global business. P&G announced in mid-October that sales continue to grow even compared to the soaring results from a year earlier. The owner of brands like Tide and Bounty is winning market share while showering investors with cash (to the tune of a projected $16 billion this fiscal year).

Wall Street is worried about rising costs, which did hurt the bottom line in the latest quarter. Operating margin fell in the fiscal first quarter, and core earnings dropped 1% even as organic sales rose 4%.

But P&G is rolling out price increases over the next few quarters. Combined with new productivity initiatives, these moves should pave the way for faster earnings growth, and market-beating shareholder returns, through 2022. P&G's dividend also yields 2.4% today, or far above the 1% rate you'd get by owning American Express.

2. Walmart

Investors aren't giving Walmart enough credit. The retailer has added tens of billions of dollars to its sales footprint since the pandemic started and is still growing. Revenue in the most recent quarter was up 14.5% on a two-year basis.

The company is far more than just a brick-and-mortar retailer, too. Its e-commerce business is on track to cross $75 billion in sales this year. Walmart has an expanding hold in tech niches, too, like digital advertising and data monetization.

In addition to those attractive growth initiatives, shareholders stand to benefit from Walmart's stellar capital allocation program. Over $14 billion should be plowed back into the business this year in ways that should support higher growth in the years to come. And Walmart is aggressively buying back its stock, with over $5 billion of repurchases through the last six months. Wall Street will eventually notice all of that good news and start rewarding shareholders for holding this stellar business.

3. Coca-Cola

Coca-Cola might be the easiest call on this dividend list. Sure, the beverage giant might take a small step backward as it deals with the latest resurgence of COVID-19 cases across many key markets. But its fiscal second-quarter results showed what's likely when the pandemic threat finally fades. Coke posted expanding market share and soaring profits in that period, with gushing cash flow to boot.

A Coca-Cola investment exposes investors to some of the highest profit margins in the consumer staples industry and sales that steadily grow in all but the most unusual economic conditions.

And the best news is that the underperformance of the stock has pushed its dividend yield back up above 3% -- more than a full percentage point above the broader Dow. It isn't often that investors get a chance to buy such a strong business with immediate income, too.