Blackstone Group shares rose 13 percent in their stock market debut Friday, as investors scrambled for a piece of the sixth-richest initial public offering in U.S. history.

Chief Executive Officer Stephen Schwarzman now controls a firm whose market value stands near $38 billion.

The strength of Blackstone’s debut marks a coming of age for the once-secretive private equity firm, as it joins Wall Street’s publicly traded top-tier investment houses.