The IPO market has been hot this year, with more than 200 offerings raising over $70 billion. Of these IPOs, 30 were Chines companies, making 248 U.S. exchange listed China-based companies totaling $2.1 trillion in market value. Now, new rules by the Chinese government may slow Chinese domiciled companies listing on U.S. exchanges. The Chinese State Council stated that it would update the rules for "the overseas listing system for domestic enterprises"and tighten restrictions on cross-border data flows and security. China has already launched an investigation into ride-hailing app Didi. And Nasdaq-listed Weibo has announced plans to go private.