The path to the S&P 500 is apparently lined with energy drinks.

Monster Beverage (Nasdaq: MNST) has been tapped to replace Sara Lee (NYSE: SLE) in the popular stock index after the food giant splits into two companies next week.

The move is naturally validation for Monster, one of the market's biggest winners over the past decade.

Monster isn't even the world's biggest energy drink company. Austria's Red Bull is the category killer here. However, Monster's heady growth in a category that even Coca-Cola (NYSE: KO) hasn't been able to successfully penetrate has drawn investors to buy into the Monster story.

The debt-free and cash-rich company even made big news earlier this year on loud rumors that Coca-Cola was looking to acquire the company. The chatter failed to pan out, and now Monster gets to join the large-cap elites that make up the 500-stock index.

These are interesting times when it comes to energy drinks. Kraft's (NYSE: KFT) MiO line of water enhancers has been aggressively marketing its MiO Energy product. A squirt of MiO Energy's Black Cherry or Green Thunder turns ordinary water into an energy drink.

Monster fans will argue that it's the carbonated zing that makes its energizer different than MiO's portable solution, but SodaStream (Nasdaq: SODA) has also been pushing its home-based water carbonator and the availability of an energy drink syrup that packs the flavor and adrenaline pop that energy-drink fans crave.

The good news for Monster is that the new competition hasn't gotten in its way. Net sales and profits soared 28% and 38% respectively in its latest quarter.

The S&P 500 is getting a true growth stock here.

The valuation's steep. Monster is fetching 37 times this year's projected profitability and a still heady 30 times next year's earnings. It may get even more expensive in the coming days. Index funds and other S&P 500 trackers will need to buy into the stock when it officially gets added to the index after next Thursday's close.

You blew it, Coke. You should've bought in when you had a rumored chance.

Drink up
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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.