Roger Federer invested early in this shoe company — its stock has skyrocketed out of the gate

Tennis great Roger Federer has reason to smile this week, not because he has a ton of money and 20 Grand Slam titles.

Back in 2019, Federer inked a partnership with high-end running sneaker brand On Holding. Federer also invested an undisclosed sum (at an undisclosed valuation) in the maker of sneakers with "cloud" soles, and has since worked alongside the brand to develop his own footwear line dubbed "The Roger."

Federer's stake is very likely worth multiples more amid an enthusiastic response to On Holding's IPO debut this week.

Shares of On Holding exploded 46% to $35 on its first day of trading on the New York Stock Exchange on Wednesday. On Holding (ONON) priced its IPO at $24, the high end of an expected $20 to $22 range.

Shares popped another 15% to $40 on Thursday.

A woman wears On shoes outside the New York Stock Exchange before the company's IPO, Wednesday, Sept. 15, 2021. (AP Photo/Richard Drew)ASSOCIATED PRESS

ON Holding now has a $10 billion market cap, a shade above the more established retailer Under Armour at $9.44 billion. Nike remains the king of the space, however — its market cap stands at $250 billion.

"It's great," On Holding co-CEO Marc Maurer said on Yahoo Finance Live about business trends right now.

That indeed appears to be the case.

For the six months ended June 30, sales for the Swiss-based On Holdings rose 85% to 315 million francs ($56.49 million). Adjusted EBITDA [earnings before interest, taxes, depreciation and amortization] rose to $47.3 million francs ($8.48 million) from 15.9 million francs ($2.85 million) a year ago.

On Holding is looking to capitalize on the interest in green-friendly apparel and footwear, debuting a $29.99 a month subscription program that recycles a person's sneakers and ships them a new pair. The company also believes the return to office after the pandemic will be a key sales opportunity.

"After the pandemic, we will see people coming back to the office and they are not going to put on their leather shoes. They are going to go in sneakers. They are going to wear their sports clothes," On Holding co-founder and co-executive chairman Caspar Coppetti told Yahoo Finance Live.