Dropbox Inc. priced the initial public offering of 36 million shares of its common stock at $21 per share, above the estimated price range of $18 to $20 per share.

The shares began trading on the Nasdaq Global Select Market March 23 under the symbol DBX, quickly adding over 40% of the IPO price. The stock traded as high as $31.60 per share March 23 and was at $29.75 per share as of about 1:30 p.m. ET, up approximately 41.7% from the IPO.

The San Francisco-based file-sharing and cloud-storage company is offering 26,822,409 shares of class A common stock, while the selling stockholders are offering 9,177,591 shares of class A common stock. The offering is expected to close March 27, subject to customary closing conditions.

Dropbox also granted the underwriters a 30-day option to purchase up to 5.4 million additional shares of class A common stock at the initial public offering price, less underwriting discounts.

Goldman Sachs & Co. LLC and J.P. Morgan Securities LLC are joint lead book-running managers. Deutsche Bank Securities, Allen & Co. LLC, Bank of America Merrill Lynch, RBC Capital Markets, Jefferies, and Macquarie Capital (USA) Inc. are acting as joint book-running managers.

Canaccord Genuity, JMP Securities, KeyBanc Capital Markets and Piper Jaffray are acting as co-managers for the offering.