The latest 13F season is commencing, 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 Bridgewater Associates, one of the world's largest hedge fund companies. According to its recently released 13F statement, the company has reduced its positions in Hewlett-Packard Company (HPQ -1.61%) and Sysco Corporation (SYY 0.03%), while eliminating its position in Valero Energy Corporation (VLO 2.48%).

Hewlett-Packard has been suffering in recent years, in part due to a weak PC market, which is expected to shrink by 6% in 2014, per analysts at IDC. Its last quarter featured estimate-topping revenue and earnings, with earnings rising 10% over year-ago levels, and revenue dropping by 1%. The company has been cutting costs aggressively, but its enterprise services business has not been growing as quickly as hoped. Goldman Sachs has slapped a sell rating on the stock. The printing giant plans to compete in 3-D printing, and it has been racking up some significant contracts, such as one worth up to $32 million from the Department of Homeland Security, and one worth up to $548 million with the Department of Defense. It's also expanding in health-care analytics, and generating solid free cash flow. Hewlett-Packard's stock has surged nearly 50% during the past year, and yields 1.9%. With its forward price-to-earnings (P/E) ratio near eight, some see more growth ahead for the stock.

Sysco is a giant in food delivery to restaurants and other institutions and a dividend dynamo, recently yielding 3.2%. In its second quarter, it topped earnings expectations (though earnings were down over year ago levels) and disappointed on revenue (though that rose). Bears worry about how rapidly it can grow, with some seeing it as a good company in a bad industry. Bulls like its market dominance, consistent profitability, and reliable quarterly payout. Its international expansion offers more cause for optimism.

Major U.S. refiner Valero Energy yields 2% and has gotten a boost recently due to instability in the Ukraine. In 2013, a drop in the spread between Brent and WTI crude prices hurt its profit margins, but Valero still upped its throughput during the year, and its significant capital expenditures in 2014 could lead to further growth. Valero's competitive advantages include its size and the location of its operations, and it has been a successful major player in ethanol. Valero is poised to benefit from the proposed (and controversial) Keystone XL Pipeline, and has been investing in railcars to help bring in crude from inland fields. Bears worry about rising crude prices, though, and would like to see more growth drivers for the company.