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.

Confident that Federal Reserve chair nominee Janet Yellen will keep interest rates low for another few months, investors are once again in buying mode today. As of 1:05 p.m. EST the Dow Jones Industrial Average (^DJI 0.40%) is up 44 points, or 0.28%, and now sits at 15,920 for what would be an all-time closing high. The S&P 500 is also climbing and could also set a new record if the index closes at its current level, up 0.1% at 1,792. The technology-heavy Nasdaq is also up 0.1%.

A few winners and losers
One of the big winners within the Dow today is ExxonMobil (XOM -3.54%) up 1.3% at this time after Warren Buffett's Berkshire Hathaway disclosed yesterday that it had taken a 40 million-share stake in the oil and gas company -- a holding worth about $3.45 billion. Due to the type and nature of the company, many believe Buffett himself picked Exxon for Berkshire's portfolio. 

Another stock receiving a boost after a big fund manager disclosed ownership is J.C. Penney (JCPN.Q), which is up 5.2% at this time. David Tepper's Appaloosa Management reported that it took a 737,000-share stake worth about $6.5 million. While this is certainly a much smaller stake than what we saw with Buffett, J.C. Penney is in much worse shape than Exxon ever has been. The mere fact that anyone at an investment company believes J.C. Penney is worth even a small amount is enough to get others excited and push up the stock price, even if it is just a temporary move.  

Investors shouldn't follow these moves into these companies unless they have done their own research and found that one of these stocks fits their mold of a good opportunity. Never walk blindly into something, regardless of who is giving you directions.

In other news, shares of McDonald's (MCD -0.62%) are down more than 1% today after McDonald's USA president Jeff Stratton told participants at a Thursday investor meeting that the company may have introduced too many new products too quickly. This, he explained, increased the complexity of preparing orders and thus service slowed down. This has caused the company to lower renovation plans for next year to just a few hundred stores and invest in new food preparation tables for all stores, which should help with the food prep and speed problems. While the menu changes have been exciting for investors and given customers more variety, this is a great example of too much change too quickly. Still, investors shouldn't worry, as this does not seem to be a long-term issue.