Professional Diversity Network’s (NASDAQ: IPDN) IPO fell flat in its market debut yesterday, getting the March initial public offerings market off to an inauspicious start. The first stock to go public on a U.S. market in nearly three weeks, the Professional Diversity Network IPO declined 4% in its first day of trading and is down another 5.6% today. That doesn’t bode well for the provider of online networking and job opportunities for minorities, which went public below its expected range at $8 a share. It was also a lukewarm kickoff for the March IPO market on the heels of a busy first two months of 2013 . Twelve companies went public in January – the most since 2006. February brought another eight IPOs – less than the last two Februarys, but more than the previous three. The returns have been even better. Year-to-date, the 21 companies that have gone public have returned an average of more than 15%. Only five of them have actually fallen since their debuts – another bad sign for Professional Diversity Network. Up next on the IPO schedule are Artisan Partners Asset Management , a Wisconsin-based investment management business, and Silver Spring Networks , which provides smart grid products and services. According to IPO web site Renaissance Capital, no other public offerings are in the hopper – which could bode for a slower March than in recent years.