????Today's $3.8 billion offering for hospital chain HCA Holdings Inc. (HCA) brought 2011 IPO volume to $12.5 billion, which is six times larger than volume at this time last year. Moreover, there have been more IPOs this year than in 2008, 2009 and 2010 combined.
????Five of the 10 largest offerings have been for private equity-backed companies, including HCA, Kinder Morgan (KMI) and Nielsen Holdings (NLSN).
????More than half of the total offerings have been for VC-backed companies, including InterXion (INXN) raising $264 million, Demand Media (DMD) raising $151 million and Gevo (GEVO) raising $107 million.
????NYSE has a slight 11-10 edge over the Nasdaq in terms of listings, although approximately 94% of the IPO proceeds went to NYSE-listed companies. Goldman Sachs is the leading underwriter, with 21.9% of the market.