The end of the summer was a mixed bag for the U.S. IPO market, with deal flow improving but new stock pricing becoming tougher.

The pace of initial public offerings picked up in July and August after a slow June, when only four deals made it to market in the wake of Facebook Inc.'s (FB) disappointing performance in late May. July and August racked up 17 IPOs, the same amount as in 2011. Among the late-summer deals that managed to debut were soccer club Manchester United PLC (MANU), teen retailer Five Below Inc. (FIVE), and travel-website company Kayak Software Corp. (KYAK). No additional IPOs are expected for the remainder of August, thanks to the U.S. market's traditional summer holiday hiatus that lasts until mid-September.

While the pace of deals was improved from June, pricing a deal within the expected range became increasingly difficult as the summer drew to a close. Of the last 10 IPOs to price, eight sold shares below their ranges.