Warren Buffett-backed Snowflake Inc.'s shares more than doubled in value in a volatile debut on the New York Stock Exchange on Wednesday, after the data warehouse company raised over $3 billion in the largest U.S. listing so far in 2020.

The debut is a big win for Buffett, who rarely invests in IPOs, as Berkshire Hathaway Inc. made over $1 billion on Snowflake's listing.

"The fact that Salesforce and Berkshire Hathaway were both in the offering on a private placement added even more fuel to the fire," said Jeff Zell, senior research analyst and partner at IPO tracking firm IPO Boutique.

Snowflake shares (SNOW) started trading at $245 apiece on Wednesday, more than double its $120 IPO price, and closed up 111% at $253.93 to value it at over $70 billion.

Among U.S.-listed companies with a market capitalization of at least $10 billion, only three companies now are more expensive than Snowflake's 2020 revenue multiple, according to Refinitiv.

Snowflake's initial public offering price was $120, well above the offer range of $100 to $110. It had on Tuesday raised $3.36 billion selling 28 million shares in the biggest software IPO of all time.

For a big IPO, an opening pop of this magnitude is rare.

The stunning debut also makes Snowflake CEO Frank Slootman and CFO Mike Scarpelli billionaires, even though neither of them founded the company.

Slootman, who has previously taken two other companies public, and Scarpelli were both hired last year to help Snowflake get ready for an IPO.

The company was founded in 2012 in San Francisco by two former Oracle veterans, Benoit Dageville and Thierry Cruanes. For the fiscal year ended 2019, Snowflake's revenue surged 173.7% to $264.7 million from a year earlier.

The blockbuster opening comes in the middle of a massive boom in U.S. capital markets following a rebound in demand for new listings, after the COVID-19 pandemic forced many companies to put off their plans to go public earlier this year.

Prior to Snowflake, Royalty Pharma and Warner Music Group Corp had the biggest stock market debuts this year.

Goldman Sachs, Morgan Stanley, J.P. Morgan, Allen & Co. and Citigroup were the lead underwriters for the IPO.