https://www.reuters.com/article/us-doximity-ipo/social-network-for-doctors-doximity-targets-4-billion-valuation-in-u-s-ipo-idUSKCN2DR1A6 >(Reuters) -Doximity Inc, a social network for doctors, is looking to raise nearly $536 million through a U.S. initial public offering, targeting a valuation of about $4 billion, according to a regulatory filing on Tuesday.