Madison Air Solutions, the largest IPO of 2026, saw its shares surge when it began trading on the NYSE early Thursday afternoon. The favorable reception for the filtration and ventilation specialist is a good sign for the IPO market, which is due to absorb megadeals from SpaceX and big AI companies later this year.

Madison Air Class A shares closed at $31.75, up 17.6% from the IPO price of $27 set Wednesday. The company offered 82.7 million shares and raised $2.2 billion, topping a $1.5 billion IPO from Forgent Power Solutions in February. The Madison Air deal was priced at the top end of the pricing range of $25 to $27 a share.

Madison Air now is valued at about $15.5 billion based on about 490 million outstanding shares. It is trading under the ticker MAIR.

Madison Air has grown through acquisitions and owns businesses including Nortek Air Solutions, a heating and cooling systems manufacturer, and April Aire, which makes air purifiers.

The company’s shares are richly valued based on Barron’s calculations.

The company trades for about 35 times its adjusted net income of about $450 million in 2025 and 20 times 2025 adjusted Ebitda (earnings before interest taxes, depreciation and amortization) of $937 million in 2025.

The company has an enterprise value (equity market cap plus debt) now of close to $19 billion. The company is using proceeds from the IPO to pay down what had been an ample debt load.

HVAC stocks have done well this year, in part due to soaring demand for keeping artificial-intelligence data centers cool. Data centers make up just 13% of Madison Air’s revenue.

In an interview, CEO Jill Wyant said Madison Air is capable of generating mid-single digit revenue growth and low double-digit growth in earnings per share. She said the company has focused niche markets in the HVAC area that involve customized solutions in the commercial and residential markets, including data centers, semiconductor factories, drug manufacturing facilities, and hospitals, where clean air is critical.

She said the company doesn’t play in the traditional residential HVAC market and instead is focused on air purification solutions. She noted that over 90% of homes lack such purification systems. The company’s sales mix is roughly 63% commercial and 37% residential.

Among HVAC stocks, comparables include Carrier Global, Lennox International, and Trane Technologies.

In addition to the Class A shares, Madison Air has agreed to sell $100 million of its Class B shares in a private placement to an entity controlled by the company’s billionaire founder, Larry Gies.

The successful debut is a coup for Gies who assembled Madison Air through a series of acquisitions. He owns 15% of the company, a stake now worth over $2 billion. Gies controls the company through supervoting B shares.

The company has granted underwriters a 30-day window to buy an additional 12.4 million Class A shares at the IPO price.

Madison Air said in a statement Wednesday that its goal was “to make the world safer, healthier and more productive through the power of better air.”