Summer warmth returning across the northern hemisphere has consumers' increasing thirst for a cool, refreshing beverage. Add to that a ramp-up in demand from foodservice specialists like restaurants seeing an easing or elimination of many stringent coronavirus-related lockdowns, and you have beverage stocks like Coca-Cola (NYSE:KO) and Monster Beverage (NASDAQ:MNST) expecting a boost in revenue for the rest of the year.

While at first glance the beverage giant Coca-Cola appears the clear winner between these two stocks, there are some reasons you might want to consider the plucky energy drink maker as a potential addition to your stock holdings, too.

1. Coca-Cola: not currently focused on growth

A titanic enterprise with quarterly revenue in the billions and a presence in nearly every country on Earth, Coca-Cola is a solid business that weathered the pandemic largely intact. Its stock price fell alongside other stocks this past year, but it continues to churn out fizzy beverages and held a 43.7% soft drink market share in the U.S. in 2019, according to Statista.

A soft drink being poured into a glass from a blue aluminum can, against a red background.

Image source: Getty Images.

Coca-Cola's share price has basically been flat since the start of the year. While it has risen roughly 23.4% over the past five years, the S&P 500 has soared about 107% over the same period.

There are many reasons for Coca-Cola's relatively sluggish growth, including the maturity of many of its markets. Management has made some efforts to account for this, initiating a lengthy process of streamlining its operations and chopping out the deadwood, but revenue has declined annually since 2012 (with the exception of positive growth in 2019). COVID-19 definitely had an effect on revenue, but it is bouncing back from the 2020 trough. Even here, though, the rebound is modest during the first quarter of 2021, gaining 4.9% year over year.

The relative stability of Coca-Cola's earnings per share (EPS) despite the steadily lessening revenue is a barometer of the company's success at controlling costs while making its operations leaner and more efficient. Beverage Daily noted in February 2021 the company has approximately halved its number of brands, shutting down some 200 "zombie brands" so it can focus resources on promoting and improving the remaining 200 "master brands."

CEO James Quincey told Beverage Daily that Coke's strategy aims at "finding a way to be able to identify the biggest bets within the innovation pipeline." Quincey listed two major initiatives for 2021 -- the introduction of Topo Chico hard seltzer and Coke Energy energy drinks -- but Coke Energy was discontinued in mid-May. Energy drinks are a popular category, with estimates projecting a 7% compound annual growth rate (CAGR) through 2025. The total energy drink market was worth more than $57 billion in 2020, and Food Navigator USA cites Beverage Digest figures indicating Coke Energy only accounted for 0.7% market share in 2020, compared to Monster Beverage's 15% share.

One strength that Coca-Cola enjoys that Monster Beverage hasn't developed yet is a strong dividend. Coke has earned its status as a Dividend King, with over a half-century of reliable yearly dividend growth, and its yield frequently topping 3%. Monster doesn't even have a dividend, let alone one paid and increased steadily for 59 years.

2. Monster: the high-growth energy drink dynamo

Where giant Coca-Cola seems preoccupied with internal reshuffling to the point of allowing its revenue to slide gradually downward for nearly a decade, the smaller Monster Beverage is projecting dynamism, even if there are a few speed bumps along the way. In the short term, a shortage of aluminum cans reduced Monster's Q1 2021 sales below forecasted levels, but during the June 15 shareholder meeting, executive comments during the question-and-answer session revealed a slowdown in the seltzer category freed up can supplies to instead be used for energy drinks, and that significant supply from China and elsewhere in Asia should become available to Monster's North American and European operations starting in July.

Monster's sales have increased strongly in recent years, including the early stages of the COVID-19 pandemic. Its Q1 2021 sales jumped to $1.24 billion, beating both Q1 2020's $1.06 billion and the pre-pandemic Q1 2019 revenue of $946 million, showing the gains aren't just an artifact of a rebound from coronavirus lows. First-quarter revenue rose by 11.2% year over year in 2019, 9.9% in 2020, and 17.1% in 2021, showing ongoing momentum across multiple years.

At the bottom line, Q1 adjusted earnings per share (EPS) of $0.59 jumped 14.2% year over year from 2020's $0.52 EPS. Q1 2019 EPS amounted to $0.48, so once again, Monster is outperforming a successful pre-pandemic year with 2021's first few months, too.

While market share has declined slightly in a few markets where new COVID-19 lockdowns were recently rolled out, such as India and Australia, Monster's executives also reported during the June 15 Annual Meeting of Shareholders that the company has seen strong market share gains in South American countries such as Argentina and Chile, Asian nations like South Korea and Japan, and several European countries.

With a strong handle on capital expenditures (CAPEX) and a balance sheet largely free of long-term debt, Monster's net income margin has risen higher than 30%. The company has also built up nearly $2.2 billion in cash, which, given its low expenses outside the temporary issue of aluminum can supply, positions it for several possible initiatives, including stock buybacks improving the value of investors' holdings, acquisitions, new product launches, and so on.

energy drink cans sit in ice

Image source: Getty Images.

Coca-Cola versus Monster: Which is the better choice?

Both Coca-Cola and Monster are solid companies to have in your portfolio, with Coke offering excellent dividends and Monster keeping up steady, generally double-digit percentage year-over-year growth in the popular, and expanding, energy drink category. Ideally, if you're investing in beverage stocks, you'd want to have shares of both, and add to your stake as opportunity allows.

If you need to choose one or the other, however, Monster might be a slightly better pick. The outcome of Coca-Cola's long, drawn-out internal restructuring plan remains unknown, especially in light of the failure of Coke Energy to make positive inroads in one of the modern market's prospering categories. Monster, on the other hand, is growing its top and bottom lines right now, and powered robustly through COVID-19 with little loss of momentum.

Finally, if the vague rumors eventually prove correct and Coca-Cola (already a 19% stakeholder in Monster) acquires the energy drink maker outright, the company's energy beverage success will likely transfer over to Coca-Cola, bringing Monster's vigorous growth and Coca-Cola's massive reach and resources together into a single entity likely to be rewarding for shareholders in either enterprise.

 
This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.