Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

The Dow Jones Industrials (^DJI 0.69%) is up 32 points as of 11:30 EDT, though it had gained nearly 100 points prior to the release of the ISM Manufacturing Index and comments from Federal Reserve Governor Jim Bullard.

The ISM report indicated that manufacturing activity in the U.S. was better than economists had expected. Although that report appears positive for the U.S. economy, and therefore U.S. stocks, it may increase the likelihood that the Federal Reserve reduces its purchases of long-term asset, which have helped push the market to new highs. On Wednesday, the Fed said it would wait for more evidence before reducing its purchases -- a stronger ISM Manufacturing Index is additional evidence of an improving U.S. economy.

Meanwhile, Bullard declined to speculate on whether or not the Fed would curtail its asset purchases in December, instead saying only that the Fed needed to keep its options open.

Chevron posts poor earnings on well output
Dow-component Chevron (CVX 0.57%) tumbled roughly 2% after the company posted earnings that disappointed analysts. In the third quarter, Chevron earned $2.57 per share, down from $2.69 in the prior year. Chevron cited weakness in its well-output business.

Chevron's report appears to be further evidence of an ongoing trend in its industry. On Thursday, Chevron's rival ExxonMobil reported earnings, and it, too, saw profit decrease -- in Exxon's case, 18%.

First Solar rockets higher on earnings beat
First Solar (FSLR 2.17%) meanwhile posted a huge gain on the session, rallying 16.5%. Like Chevron, First Solar reported earnings, but unlike Chevron its profit jumped. In the third quarter, First Solar reported earnings per share of $1.94, nearly double the $1 per share it reported in the same period last year.

In addition to reporting strong earnings, First Solar also raised its guidance, saying it would earn more this year than it had expected. And while First Solar's report was no doubt strong, the outsized gain in shares may have been partially due to First Solar's high short interest -- almost 17% of outstanding First Solar shares have been sold short.

J.C. Penney bounces back
Shares of department store J.C. Penney (NYSE: JCP) also moved sharply higher during the session, breaking above $7.80 after for a gain of more than 5%. It wasn't abundantly clear why J.C. Penney was strongly outperforming the market -- unlike Chevron and First Solar, the company did not report earnings.

Still, J.C. Penney has been an incredibly volatile stock in recent weeks, briefly falling to an all-time low in October after investors became concerned with J.C. Penney's ability to survive as a company. In such an extreme situation, wild swings are likely.