Earnings season has gone just about exactly the way bullish investors would have expected so far. Many companies managed to overcome lowered expectations for earnings growth and posted positive surprises that, in turn, lifted their share prices. As a result, the stock market climbed to more all-time record highs, with the Dow Jones Industrials (^DJI -0.98%) rising 78 points, and the S&P 500 (^GSPC -0.46%) matching the Dow's half-percent gain.

But two prominent Dow stocks didn't deliver on the earnings front to investors' satisfaction. Intel (INTC 1.77%) was the leading loser in the Dow, falling 3.75% after only matching earnings estimates, and falling short on top-line revenue figures. The company forecast lower sales for the current quarter, giving further evidence of the major challenges Intel faces with its PC business, as falling demand for desktops and laptops in favor of mobile devices like smartphones and tablets pose a continuing threat to the company's growth. Even if it's successful in entering the mobile market, Intel will face immense competition there that will likely keep margins relatively low compared to its legacy PC chips, where it had a commanding market share and, consequently, greater pricing power.

The other substantial loser in the Dow was American Express (AXP -0.84%), which fell 3.6%. AmEx suffered a one-two punch today, as it missed revenue estimates despite posting a record profit for its second quarter last night. The greater concern among some investors came from the European Commission, though, which is looking to follow in the wake of U.S. regulators by imposing caps on credit card and debit card transaction-based "swipe fees." AmEx argued that any move wouldn't affect much of its business, but analysts remain worried that any regulations that encourage movement toward lower-cost payment options could hurt AmEx's international business.

Finally, outside the Dow, eBay (EBAY 0.31%) dropped almost 7% after its own quarterly report, despite seeing continued growth in both its PayPal electronic payments business and its namesake auction and marketplace site. The company guided analysts toward the lower part of previously announced ranges for earnings and sales, though, as problems in key markets like Europe and Korea could hurt the company's overall results for the remainder of the year. Given the wrangling between PayPal, card companies like AmEx, and tech companies to try to come up with payment solutions for mobile platforms, you can expect plenty of jockeying for position among these companies well into the future.