Stocks are moving significantly lower today as fiscal cliff negotiations heat up again. The president and Congress are back at the negotiating table and the rumor is that a small deal is on the table today. Growing fear that we'll go over the cliff has the Dow Jones Industrial Average (^DJI -0.11%) moving 0.73% lower today and the S&P 500 (^GSPC 0.02%) has lost 0.64% of its value.

While the fiscal cliff is dragging the whole market lower, there is some specific news impacting some stocks. Hewlett-Packard (HPQ 1.55%) has fallen 2.4% today after the Justice Department said it was looking into the company's Autonomy unit. It's never good when the government begins looking at your company and the stock is selling off as a result.

Big oil isn't far behind HP, with Chevron (CVX 0.44%) falling 1.5% and ExxonMobil (XOM 0.02%) dropping 1.6% today. Investors are worried that a new EPA administrator may be harder on the oil industry than Lisa Jackson, who just resigned from the agency. There's also worry that big oil may be a target for fiscal cliff negotiations that need to raise revenue. A week ago, I highlighted a few loopholes that may be targets during fiscal cliff negotiations that would affect these companies going forward.

It's becoming more and more likely that we'll go over the fiscal cliff, and the market will likely continue a slow decline if we do. If that's the case, it provides a great opportunity for the long-term Foolish investor.