Spring is here, along with a welcome thaw to end a brutal winter. That is perhaps an apt metaphor for private equity fundraising, which also appears to be warming up. The final close of Onex Partners IV LP, the fourth partnership of Canadian private equity firm Onex Corp, provides a timely example. Fund IV has been wrapped up with US$5.15 billion in total capital committed. According to Onex, it is the largest fundraise in its history.