The latest 13F season is here, when many money managers issue required reports on their holdings. It can be worthwhile to pay attention, as you might get an investment idea or two by seeing what some major investors have been buying and selling.

For example, consider Appaloosa Management, founded by investing giant David Tepper and known for investing in the debt of companies in distress. In a letter to shareholders last year, Tepper noted that, had one invested $1 million in his hedge fund in 1993, it would have grown to $149 million over the past 20 years. Investing in the S&P 500 instead would have left you with $5.3 million. Tepper's performance reflects an average annual net gain of 28%. Wow.

Appaloosa Management's latest 13F report shows that it has decreased or eliminated its positions in Chimera Investment Corporation (NYSE:CIM), EMC Corporation (NYSE:EMC), and Freeport-McMoRan Copper & Gold (NYSE:FCX).

Chimera Investment Corporation is a mortgage REIT that invests in a wide range of agency and non-agency residential mortgage-backed investments, as well as other loans. Chimera draws great interest because of its hefty 11.6% dividend yield. It has differentiated itself from many peers by focusing more on non-agency residential mortgages (i.e., those not sponsored by government-related entities such as Fannie Mae and Freddie Mac). That's a riskier business model, but Chimera has offset some of that risk by relying less on leverage. The company, like its peers, is vulnerable to rising interest rates, but bulls are focusing on Fed chair Janet Yellen's aims to keep rates low for the time being. Meanwhile, though, Chimera has been working its way out of an accounting quagmire and has been filing financial statements late, having secured extensions from the NYSE. A recovering housing market can improve Chimera's prospects, but you can find more reliable generous dividends elsewhere. The stock isn't among the most heavily shorted, but its short interest did grow by double digits in April, suggesting growing doubt in the market.

EMC Corporation is a data storage giant positioned to profit from the rapidly growing cloud-computing and "big data" movements. It holds an 80% ownership stake in virtualization specialist VMware, too, and has made some significant acquisitions recently, such as storage software developer ScaleIO and flash equipment maker DSSD. It has a strong cloud-focused partnership with Microsoft, which is the nation's second-largest cloud-services provider. With EMC's forward price-to-earnings ratio near 12, it seems attractively priced, though its profit margins have pulled back in recent years. Its top line has been increasing slowly but steadily. It also has many initiatives that could pay off in the future, such as its RSA Security business and Pivotal, which has been likened to "an OS for the cloud." EMC initiated a dividend last year and yields 1.7%. It has also been engaging in sizable share repurchases.

Freeport-McMoRan Copper & Gold offers substantial diversification beyond gold, as it's the world's second-largest copper-producer and now also has a big oil and gas exploration and drilling business. In order to tackle its sizable debt, the company is selling its Eagle Ford shale assets as it focuses more sharply on drilling in the Gulf of Mexico. Falling copper prices are putting pressure on the company, though. Bulls see much to like about Freeport McMoRan Copper & Gold, such as its relatively low production costs, stable reserve valuations for copper and gold, and growth prospects in China. The stock yields 3.6%.

Longtime Fool specialist Selena Maranjian, whom you can follow on Twitter, owns shares of Microsoft. The Motley Fool recommends VMware. The Motley Fool owns shares of EMC, Freeport-McMoRan Copper & Gold, Microsoft, and VMware. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.