 Portillos Inc. PTLO, 42.75 received a nice ovation in its public debut Thursday, as the Chicago street food companys stock opened 30 above its IPO price, and then rose further. The company raised 405.4 million as it sold 20.27 million shares in its initial public offering, which the company said overnight priced at 20 a share, or at the top of the expected range of between 17 and 20 a share. 