As the U.S. stock market has climbed this year, initial public offering filings and pricings are also outpacing last year's figures, based on statistics from IPO research firm Renaissance Capital of Greenwich, Conn.
http://www.forbes.com/sites/sageworks/2013/05/26/4-things-you-dont-know-about-private-companies/
http://www.forbes.com/sites/sageworks/2013/05/26/4-things-you-dont-know-about-private-companies/