Most investors don't keep tabs on their companies' fundamental value. That's a mistake. If you take the time to read past the headlines and crack a filing now and then, you're in a much better position to spot potential trouble early. Better yet, you'll improve your odds of finding the underappreciated home run stocks that provide the market's best returns.

We can help you keep tabs on your companies with MyWatchlist.com, our free, personalized stock-tracking service. Here are five stocks from my watchlist that have been hot lately.

1. SandRidge Energy (NYSE: SD)
SandRidge caught my eye after it had risen by more than 65% in the past three months. Since late 2009, SandRidge has made several acquisitions, notably Arena Resources, designed to shift the company's primary focus from natural gas to oil production. SandRidge now has sizable holdings in Texas and Oklahoma in which to drill for oil. It expects that its production will swing from mainly natural gas to mainly oil in 2011. SandRidge's prescient bet on oil means the company will be a big beneficiary from this year's rising oil prices. 

2. K-Sea Transportation (NYSE: KSP)
K-Sea Transportation caught my eye after it had risen 69% over the past three months. K-Sea is a shipping transportation and logistics company for petroleum products along the U.S. East Coast. Its shares took a huge jump last week, when it agreed to be acquired by Kirby for roughly $8.15 a share. In general, oil-shipping companies' profits are expected to increase after geopolitical events have caused many disruptions in the oil-and-gas space. Read more.

3. Cirrus Logic (Nasdaq: CRUS)
Cirrus Logic has been on a tear recently. Over the past three months, the stock has risen 31%, and longer-term it's done even better. Fool analyst Eric Bleeker bought the stock for his real-money "Rising Stars" portfolio in November, and since then it's returned an astounding 65% in just five months. Check out his buy recommendation.

4. Oilsands Quest (NYSE: BQI)
Oilsands Quest is continuing on its quest to find oil. Its stock has risen 22% over the past three months after falling by more than 60% in the preceding year. Unlike other speculative oil plays such as ATP Oil & Gas (Nasdaq: ATPG) , which has producing wells and cash flow, Oilsands Quest is in the development stage, a euphemism meaning that it hasn't produced oil yet. It has spent quite some time trying to profitably drill in the Canadian oilsands, but after numerous setbacks, the company tried to sell off some of its assets to continue operating, a strategy that worked for Delta Petroleum (Nasdaq: DPTR). After that failed, the company went back to the equity markets to raise more money. At this point, Oilsands Quest is purely speculative. It's sitting on some real assets with its oilsands holdings but so far hasn't been able to monetize them. The company should be interesting to follow going forward in case its fortunes change.

5. Rediff.com (Nasdaq: REDF)
Rediff.com caught my eye after rallying 43% over the past three months. The company operates a Web portal in India much akin to U.S. portals Yahoo.com or MSN.com. Although the company isn't profitable, the opportunity before Rediff is huge. India has more than 700 million mobile-phone users but only 10.3 million broadband connections. As infrastructure expands and broadband use rises among the population, Rediff should be a winner. The company also has net current assets of $40 million, 20% of its market cap.

Foolish bottom line
If you're looking to keep up with these companies, add them to MyWatchlist.com, our free, personalized stock-tracking service. If you want some full-on stock picks, we recently wrote a report highlighting five stocks that The Motley Fool bought for its own account -- including the stock that senior writer Morgan Housel calls "probably the world's greatest investment." If you'd like to see the entire buy thesis on that stock, as well as the other the other four, I invite you to download it for free. Just click here.