Snap Inc, the owner of the popular messaging app Snapchat, set a valuation of between $16.20 billion and $18.52 billion in its initial public offering, significantly below expectations.

Snap, which filed for its IPO in early February, was widely expected to be valued at between $20 billion and $25 billion, giving the company the richest valuation in a U.S. technology IPO since Facebook (FB).

The company said in a filing on Thursday that it expects to raise as much as $3.2 billion in the IPO.

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Snap said it expected the 200 million Class A share offering to be priced within a range of $14-$16 per share.

Selling shareholders will sell 55 million shares and the remaining will be sold by the company.

Snap said it expects to use proceeds of about $2.1 billion for general corporate purposes and to acquire businesses, among other things.

Snap, which launched itself in 2012 with an app that sends disappearing messages, rebranded itself last year as a camera company and started selling $130 video camera glasses.

The company generates the majority of its revenue from advertising, seeking to challenge the dominance of existing internet giants.