Premium athleisure is a big business. Not only are people everywhere becoming more knowledgeable about the health benefits of getting a good workout, but the work-from-home trend means that people are dressing down more often.

While Nike is the biggest athletic-wear company by a large margin, there's plenty of room for competitors. Premium activewear is growing at a fast clip, led by Lululemon Athletica (LULU 1.31%), but On Holding (ONON 2.66%) is capturing market share and positioning itself as the "most" premium activewear company. Which of their stocks is the better buy today?

The case for Lululemon: Low risk, high payoff

Lululemon has made a name for itself as the top name in this category. It's carved out a niche of brand-loyal customers who love its patented fabrics and seasonless styles and are willing to pay high prices to wear them. It's achieved this through cultivating a community of like-minded fitness enthusiasts and playing to their needs with products that suit their lifestyles.

Because of its focus on affluent customers, Lululemon hasn't seen the same negative impact from inflation as other companies. In general, it manages better through economic swings, including early in the pandemic when other retailers floundered.

Lululemon reported a 19% year-over-year sales increase in the 2023 fiscal third quarter (ended Oct. 29), driven by a 13% increase in comparable sales (comps). Gross margin improved by 1.1 percentage points to 57% in the third quarter although operating margin was pressured and narrowed 3.7 points to 15.3%.

Management released a growth strategy to double sales by doubling men's and digital sales and quadrupling sales from 2021 through 2026. Lululemon only operates through direct-to-consumer channels, and digital plays a large role, accounting for 41% of total sales in the third quarter.

However, it's opening stores globally and has a current total of almost 700. It's planning to open 55 stores in 2023, with more than half in China. The company has a huge global opportunity that should drive sales growth for many years.

Lululemon has been a market-beating stock for years, gaining more than double the S&P 500 over the past five years. With its continued strong performance, there's good reason to suspect it can continue to outperform the market.

The case for On Holding: More territory to conquer

On is a younger company than Lululemon, first started in 2010, whereas Lululemon's beginnings were in 1998. It focuses on footwear but has also developed a full line of premium fitness apparel targeted to serious athletes.

Its core product is its CloudTec running shoe, which has caught on with a cult following of customers who rely on it as their everyday footwear. It targets upscale, resilient customers who can still pay full price for their favorite shoes despite inflation. On boasts a gross margin of 59% for 2023, outdoing Lululemon's.

On closed out the year with a 47% sales increase, or 55% on a currency neutral basis. It's headquartered in Switzerland and reports in Swiss francs, so its results are highly susceptible to currency swings. The company reported an annual profit in 2023 but a loss for the fourth quarter, but it's getting closer to sustainable profits.

The company is smaller than Lululemon, with $1.9 billion in trailing-12-month sales vs. Lululemon's $9 billion. It's planning to grow strategically by increasing brand awareness and expanding globally through a multichannel approach that includes a robust direct-to-consumer business, as well as through wholesale channels. On is inking deals with celebrity endorsers, such as tennis stars Roger Federer, Iga Swiatek and Ben Shelton.

On has a massive opportunity to gain more followers and customers. This could be an excellent time to buy shares before they climb.

Which premium activewear stock is the better buy?

Lululemon and On trade at strikingly similar valuations.

ONON PS Ratio Chart

ONON PS Ratio data by YCharts.

Lululemon may have the upper hand because it's already proven itself and is reliable. On, however, gets the upper hand in terms of being a smaller company with a wider opportunity.

Investors looking for more of a sure thing might want to invest in Lululemon stock, but those with a higher risk tolerance and willing to take a chance on a growth stock might want to choose On.