The Dow Jones Industrials Average (DJINDICES:^DJI) slipped 0.3% on the first day that Goldman Sachs, Nike, and Visa got their Dow membership cards. The broader S&P 500 (SNPINDEX:^GSPC) fell almost 0.5%.

Of course, not every stock fell.

UnitedHealth Group (NYSE:UNH) rebounded nearly 2% today after falling more than 5% last week. It's unclear how the Obamacare health exchanges, which start operating Oct. 1, will affect insurers. While expanded access to health insurance coverage means more customers, what health insurers really want are young, healthy customers, because Obamacare also prevents them from discriminating against people with pre-existing conditions.

What's more, for this reason, anti-Obamacare political groups have focused much of their sabotage efforts on a campaign to persuade young people not to buy health insurance. Unsure of the makeup of the initial group of customers, UnitedHealth is taking its time to enter the health exchanges.

General Electric (NYSE:GE) rose 1.1% after winning a huge $2.7 billion contract to supply Algeria with turbines for power plants. Over the weekend, a Barron's article touted GE's enormous backlog of $223 billion, or about one and a half years of the company's revenue and speculated that the company could spin off its consumer lending into a separate company.

One big winner outside the Dow today was Apple (NASDAQ:AAPL), which spiked 5% after announcing it sold 9 million new iPhones over the weekend. Apple said it expects fourth-quarter sales to be near the high end of its $34 billion to $37 billion guidance and gross margins also near the high end of its 36% to 37% guidance. Despite a mammoth $445 billion market capitalization, the stock seems reasonably cheap. Always take their estimates with a grain of salt, but analysts expect 16% growth -- quite good for a stock trading at just a P/E of 12. And that's without even factoring the company's massive cash hoard. Unless growth really starts to trail off or margins plunge, that seems to me like a pretty good deal.

Ilan Moscovitz owns shares of Apple. The Motley Fool recommends Apple and UnitedHealth Group and owns shares of Apple and General Electric. 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.