NEW YORK ( TheStreet) -- I'm cautiously optimistic that gains are more likely in the near future for the iShares Dow Jones Transportation Average Index Fund ( IYT) and other popular transportation products.Since the start of May, IYT has been stuck in a downward trend, leaving some investors with reason for alarm. According to Dow Theory, a decline below February's low would confirm the Dow's decline below February's low (at the start of July) and signal a resumption of the bear market. The recent lag in IYT, however, can largely be attributed to weak performance from top holding FedEx ( FDX), which represents 10% of the fund's total portfolio. Over the past three months, shares of the shipping goliath have fallen over 17%, causing it to carve out new 2010 lows. The recent dismal performance is in large part due to the company's poor first-quarter earnings report and negative guidance. FedEx continued to pull the transportation ETF to the downside Wednesday, as shares of FDX slipped 2.5%, but IYT fell only 1.6% and Claymore/Arca Airlines ETF ( FAA) slid just 1.9%. Still, FedEx's poor second-quarter performance is not a bellwether for other major players in the transportation industry. According to a report from Barclay's, the headwinds that face FedEx are not based on the global economy. Rather, FedEx's poor quarterly earnings report was attributed to company-specific costs including the reinstatement of employee perks, including pension and medical benefits. Fellow shipping giant UPS is scheduled to report its second-quarter earnings before today's bell and it does not appear the firm is destined to deliver a FedEx-like disappointment. On the contrary, the company's prospects appear promising. Earnings estimates for the previous quarter and the fiscal year have been consistently rising over the past three months. A strong report from UPS would add to an already positive season for the transportation industry. In recent weeks, companies including CSX, Delta Airlines ( DAL), and US Airways ( LCC) have stepped up to the plate and announced an analyst beating performance. Delta's numbers were particularly optimistic, with the firm turning out its best quarter in a decade. I feel that strong earnings performance from these firms and others in the near future will be a far stronger driver for IYT in the near future than the weakness in FedEx.