The Dow Jones Industrial Average (DJINDICES:^DJI) started off earnings season on a strong note, gaining 89 points, or 0.6%, in relatively steady trading. On a day with no major economic reports, the good feelings from last week's employment report and optimism about earnings season seemed to carry the blue chips higher. Alcoa (NYSE:AA) kicked off the quarterly announcements after hours today, as the aluminum maker slightly beat expectations with an adjusted earnings per share of $0.07 versus the consensus at $0.06, and reiterated its forecast for aluminum demand to increase 7% this year. Revenue fell 2% to $5.85 billion on lower metal prices, but that also beat estimates of $5.83 billion. After a gain of 1.4% during the trading session, shares fell back 0.25% following the report.

Tech stocks were behind the curve today, as the Nasdaq gained just 0.16%, mainly because Intel (NASDAQ:INTC) got downgrades from Citigroup and Evercore Partners, slashing 3.6% off of the chipmaker's share price. Citi analyst Glen Yeung said there was a ceiling in Intel's share price, given weakening PC sales and repeated downward earnings revisions. Evercore, meanwhile, said unit sales of Intel chips could be down as much as 10% this year as PC sales continue to fall further than expected.

On the plus side, UnitedHealth Group (NYSE:UNH) was the Dow's biggest gainer, moving up 2.1% today to a new 52-week high. Part of the jump is due to a Barron's report that said the stock could rise as much as 40% during the first two years of Obamacare. The report also said the company has an advantage over competitors because of its high-growth businesses and increasing profit margins. Contrarily, UnitedHealth may have also benefited from the announced delay in two parts of Obamacare, as many investors fear the impact the health-care law will have on the insurance industry.

Outside the Dow, Barnes & Noble's (NYSE:BKS) shares tumbled 4.9% after hours following CEO William Lynch's resignation, effective immediately, after a disappointing quarter for Nook sales. The board didn't name a successor, but the news underscores the strong headwinds the venerable bookseller faces. The Nook was once seen as the company's savior, but now it seems to have become an albatross equal to the company's bricks-and-mortar real estate.

Fool contributor Jeremy Bowman owns shares of Apple. The Motley Fool recommends Amazon.com, Apple, Intel, and UnitedHealth Group and owns shares of Amazon.com, Apple, and Intel. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.