File storage and collaboration service Dropbox Inc. saw its shares jump 36 percent today in the company’s first day of trading after its initial public offering of stock.

Shares opened trading this morning at $29 a share after Dropbox priced its IPO Thursday afternoon at $21 a share, above an already higher range of $18 to $20 a share it announced only Wednesday.

The long-awaited IPO raised $756 million for the company, which competes with a wide range of storage service providers such as publicly held Box Inc., Google LLC and Apple Inc., comes on top of a recent $100 million investment through a private placement by Salesforce.com Inc. at the IPO price. It’s the largest offering in the tech industry since Snap Inc.’s IPO last year.

Dropbox’s valuation swelled from $9.2 billion at the offering price to more than $11 billion by the end of trading today. That now tops the $10 billion the company commanded in 2014 from private investors. “It’s a good sign,” said Robert R. Ackerman Jr., founder and managing partner of the venture capital firm AllegisCyber.

The warm reception, even in the face of a 724-point or 3 percent plunge in the Dow Jones Industrial Average Thursday, could thaw a multiyear deep freeze in technology IPOs. Indeed, some observers think that thaw, fueled by the success of the relatively few IPOs last year and so far this year — cloud security firm Zscaler Inc. saw its shares more than double in its IPO last week — is just starting.

“There’s certainly more revenue-stage companies that are still private looking at when to go public,” said Matt Murphy, a partner with the venture capital firm Menlo Ventures.

Among them are Spotify AB, which is expected to make its initial offering about April 3. But there are also many smaller, more business-oriented companies, such as cybersecurity software provider Tenable Network Security Inc., which Reuters Thursday reported had hired investment bank Morgan Stanley for a possible fall IPO.

Investors are looking for better opportunities for returns in such an uncertain environment, and IPOs, including potential further price rises in weeks and months after the initial offering, could provide that. But Dropbox’s successful IPO in such a volatile market could also be unique given a combination of factors. For one, it had the Salesforce investment as an anchor for the shares. Also, a relatively small portion of overall shares in the company were offered, about 9 percent, creating a scarcity factor that can drive up the share price.

Dropbox hasn’t yet turned a profit, losing $111.7 million last year on revenue of $1.11 billion, though that loss is down significantly from $210.2 million in 2016. In its original filing, Dropbox said it would use the IPO proceeds to get more users to opt for paid subscriptions and integrate more with other software companies, following previous integrations with Google, Microsoft Corp., Slack Inc. and others.

The company has 500 million registered users, 100 million of whom have signed up since the start of 2017, but only 11 million paid users. Some 300,000 teams also use its beefier Dropbox Business service, which starts at $12.50 a month for teams of three users.

Investors, including VC firms such as Sequoia Capital and Accel and mutual funds such as T. Rowe Price and Fidelity Investments, have sunk more than $600 million into the company since it was started 11 years ago.

Despite the size of the offering, co-founder Drew Houston (pictured, left of center) isn’t losing much control to public investors. The shares offered constitute just 2 percent of the voting rights, according to CNBC, while the rest will be Class B shares currently held by Houston and other major investors.

The main underwriters for the offering are Goldman Sachs Group Inc. and JPMorgan Chase & Co., though the filing lists many other participating banks: Deutsche Bank Securities, Allen & Co. LLC, BofA Merrill Lynch, RBC Capital Markets, Jefferies, Macquarie Capital, Canaccord Genuity, JMP Securities, KeyBanc Capital Markets and Piper Jaffray.

The company’s shares trade under the ticker symbol DBX.

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