Throughout most of 2013, you could count on the Dow Jones Industrials (^DJI -0.99%) to recover from early losses to post impressive gains by the market's close. Yet lately, the stock market has been reversing that trend, with today marking a perfect example. After climbing to a gain of more than 75 points, the Dow steadily worked its way lower throughout the day, and by the close, the Dow finished down almost 43 points. The broader stock market was closer to unchanged, with drops in bond yields and gold prices offset by oil prices that came closer to the $100 per barrel level on fears about unrest in Egypt and the potential impact on oil flows through the Suez Canal.

Yet a couple of important stocks posted significant declines in response to news events. General Electric (GE 1.24%) fell 1.9% as it decided not to challenge a regulatory finding by the Financial Stability Oversight Council that the company's GE Capital arm is a systemically important financial institution, a term of art that imposes more regulations on the conglomerate's financial services segment. The move seems somewhat surprising in light of the company's numerous efforts to deemphasize its formerly dominant GE Capital division to favor other businesses like energy, but the division still represents a substantial part of GE's overall business, and a future financial crisis could do its share of damage to the stock.

Boeing (BA 1.09%) also fell, dropping 1.7% and marking a much bigger drag on the Dow because of its relatively high share price. A report from Bloomberg noted that United Continental, the only U.S. airline that's currently flying the new 787 Dreamliner aircraft, has cancelled Dreamliner flights at roughly quadruple the rate of its other airplane models. Undoubtedly, awareness of potential problems for the Dreamliner is at a heightened level in light of the battery problems that grounded the new model for months earlier this year. But at some point, Boeing needs to get past these problems in order to assure investors that it can move forward to focusing on actually delivering on the vast backlog of existing orders for the 787 and other aircraft.

Outside the Dow, energy investment vehicles Linn Energy (LINEQ) and LinnCo (NASDAQ: LNCO) fell 19% and 17% respectively after revealing that the SEC was investigating the companies. As Fool contributor Sean Williams reported earlier today, it appears that the investigation will center on Linn's handling of accounting procedures, especially in connection with hedging strategies that the company has used. With LinnCo holding limited liability company units of Linn Energy, both companies' fortunes are tied to the results of any investigation the SEC eventually conducts.