Is Silicon Valley's piece of the IPO pie shrinking?

"We've been hearing a lot about buyout funds recently, and now there's evidence to suggest they may be replacing the valley's hundreds of smaller venture capital firms as the primary backers of companies that go public. While we saw 22 Silicon Valley venture-backed companies go public last year, we've only seen one local company go public so far this year -- Threshold Pharmaceuticals -- which was relatively small, at $37.33 million. Could there be a link?"

[SiliconBeat.com]