A "Supernova" is hitting the New York Stock Exchange. The blank-check company went public Wednesday after raising its IPO from $300 million to $350 million Tuesday due to increased demand. Supernova is led by Spencer Rascoff, an entrepreneur who co-founded Hotwire, Zillow, dot.LA and Pacaso, and led Zillow as CEO for nearly a decade. Spencer joined Closing Bell and explained why more and more companies are going the SPAC route.