Here is an article that discusses it.

The company hasn't disclosed what it will price its shares at or how much it wants to raise from the offering, but did say that its shares will be listed on the New York Stock Exchange with the ticker PINS. The latest estimates, based on Pinterest's multiple rounds of funding, put the company's valuation at around $12 billion.

https://www.fool.com/investing/2019/03/25/pinterest-ipo-4-key-points-from-the-companys-finan.aspx

Reddit is a $2B-$3B valuation.