TALI ARBELNEW YORK (AP) â¿¿ After more than a month of mostly weak returns on initial public offerings, postponed deals and a highly volatile stock market, this week's seven scheduled IPOs may be lucky just to make it to market. So far this month, four IPOs have been indefinitely postponed and one company withdrew its plans to go public. Two more companies canceled their IPOs in late April. Of the 15 public debuts in April and May, nine companies have priced below or at the very bottom of expectations. Shares of 10 of those companies are currently trading below their offering prices, meaning two-thirds of initial IPO investors have lost money if they hung on to their stakes. Not a great environment for IPOs. Only one company this week, Niska Gas Storage Partners LLC, is drawing an overall thumbs-up with its planned $367.5 million offering. That's because of the recent success of another natural gas storage company, PAA Natural Gas Storage LP, a former division of Plains All American Pipeline LP, said IPO analyst Scott Sweet of IPOBoutique. Niska is the biggest independent operator of natural gas storage assets in North America. The other deals will have to settle for "a wing and a prayer," said John Fitzgibbon, who tracks market chatter on upcoming IPOs at IPOScoop.com. "It's an ambitious calendar and they ran into something called Greece." Debt problems in Europe, particularly in Greece, have driven stock markets lower across the globe. Stocks were highly volatile at the end of last week with the Dow down nearly 1,000 points on Thursday alone before recovering most of its losses. In an effort to soothe panicky markets, the 16 countries that use the euro and the International Monetary Fund agreed this weekend to create a nearly $1 trillion rescue fund to support European nations burdened by heavy debt loads.