The giants of private equity have been taking a pummelling

Private equity firms just wrapped up a pretty rough third quarter.

Blackstone, KKR and The Carlyle Group reported disappointing results, each posting losses in their earnings reports.

Blackstone reported a loss of $0.40 per share, while KKR reported losses of $0.42 a share, and Carlyle reported a $0.43 loss.

It's not happening for any singular reason.

Carlyle announced results on Wednesday October 28, and said some of its hedge fund businesses underperformed and that the firm saw certain energy investments falter.

The underperformance of investments in Asia was partly to blame for the losses at KKR, while at Blackstone chief Steven Schwarzman blamed market volatility for the loss.

It's the latest in a series of disappointing revelations for the buyout business, which could also be seeing the beginning of the end for the IPO window that has generated so much in returns for top PE investors.

Apollo, which is thus far the only private equity firm to report a profit let alone a beat for the third quarter, did so on the strength of one of its insurance investments.

Oaktree Capital Group is the only marquee private equity firm yet to announce its third quarter numbers.

The share price of the five private equity companies are down for 2015 year to date.