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.

A day after breaking its three-day losing streak on Tuesday, the S&P 500 Index (^GSPC -0.16%) was back at it again today, falling for the fourth time in five sessions. While newly released minutes from the Federal Reserve's December policy meeting show confidence in a recovering U.S. economy, Wall Street gets uncomfortable with too much confidence. The fear is that overconfidence could mean that the central bank's record bond-buying initiatives disappear more quickly than expected, driving interest rates higher and putting the brakes on an endless recovery. While not enough to cause an outright sell-off, the S&P 500 lost 0.4 points, or less than 0.1%, to end at 1,837. 

Hewlett-Packard (HPQ -0.81%) ended as one of the index's worst performers Wednesday, shedding 2.6%. There was little amiss on the face of things that would obviously precipitate a slump, but a few behind-the-scenes factors remain in play here. Firstly, Hewlett-Packard stock has rallied nearly 80% in the last year, as CEO Meg Whitman tries to reposition the company in an age of declining PC sales -- investors may think now's a good time to take a few chips off the table. Second, HP is in the early stages of competing with a newly private Dell, a Dell that can compete without worrying about what the market will think of its quarter.

Newmont Mining (NEM -0.47%), a Colorado-based company that mines for copper and gold, saw shares fall 2.3% today. Newmont Mining is more or less a pure play on the price of gold, though last year it plummeted even harder than the price of the shiny metal, which itself fell almost 30%. Meanwhile, stock in the Colorado miner closed as the worst-performer in the S&P 500, losing 50% of its value. If the dollar continues to gain strength, gold prices will likely continue to suffer and Newmont shareholders should put on their hardhats because it could be a rocky ride. Gold ended slightly lower today, closing at $1,225 an ounce.

Finally, oil refiner Tesoro (ANDV) shed 2.2% after a downgrade hit the stock. Investment banker and equity research boutique Howard Weil, which focuses its sights on the energy sector, demoted the stock to "sector perform" from "sector outperform." While the investment bank sees upside in the refining industry for 2014 as the oil supply grows, the downgrade cites valuation and volatility as two reasons for the muted outlook. As always, remember that while stock prices may, in the short-term, react to Wall Street jibberjabber, a company's success or failure is independent of the noise on the sidelines.