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.

After a horrible January, the stock market began the new month on an even gloomier note, with the Dow sinking more than 325 points to bring its losses for the year to more than 1,200 points. But even in the worst markets, you can usually find a few brave stocks that managed to gain ground, and Herbalife (HLF -0.79%), TASER International (AXON 0.65%), and Randgold Resources (NASDAQ: GOLD) all bucked the downward trend to post decent gains today.

Herbalife (HLF) climbed 7% after the nutritional and personal-care products company released preliminary results for its fourth quarter and full 2013 year. The company said it expects fourth-quarter revenue to rise by nearly 20%, with earnings to come in about 8% to 11% above what investors had projected. Although the company's decision not to raise its full-year guidance for 2014 was a bit disappointing, Herbalife's decision to boost its repurchase authorization by half to $1.5 billion could support the stock's gains going forward.

TASER International (TASR) got good news from an unusual source today, as the stock rose 5% when the stun-gun maker found out that it will become part of the S&P SmallCap 600 Index. The change will take effect after tomorrow's close, and long-term investors hope that the move will be only the first of many such index admissions and promotions in the company's future. More important will be whether the company can boost sales and profits enough to justify its current valuation, which like many newly admitted index stocks is at somewhat lofty levels right now.

Randgold Resources (GOLD) gained 4% as the company managed to issue a reasonably strong earnings report. Predictably, net income plunged more than 35% for the full 2013 year due largely to the massive drop in gold prices. Yet gold production levels climbed almost 15% to 910,000 ounces, and Randgold believes it can boost production by another 25% to 30% in 2014. Randgold also kept its dividend steady, marking confidence that its low cast costs of $715 per ounce will allow it to stay profitable even in a tough gold market.