Every quarter, many money managers have to disclose what they've bought and sold, via "13F" filings. Their latest moves can shine a bright light on smart stock picks.

Today, let's look at Fisher Asset Management, founded in 1979 by Ken Fisher. You may know Fisher by his longtime column in Forbes magazine, where he's also No. 271 in the magazine's list of the 400 richest Americans, with a net worth of $1.9 billion. You may know his father as well: Phil Fisher wrote the seminal investing text, Common Stocks, Uncommon Profits.

The company's reportable stock portfolio totaled $36.4 billion in value as of March 31, 2013. It manages money for more than 100  large institutions, and its strategy involves macroeconomic research and fundamental analysis.

Interesting developments
So what does Fisher's latest quarterly 13F filing tell us? Here are a few interesting details:

The biggest new holdings are Coinstar and Vishay Intertechnology. Other new holdings of interest include the railroad company CSX (CSX 1.07%), which operates more than 21,000 miles of track and is yielding 2.3%. It has been hurt by softness in demand for coal (in part due to low natural gas prices), but coal is likely to remain in demand internationally, and coal exports have been increasing. CSX is geographically well positioned to benefit from such exports, with its access to Eastern and Gulf Coast ports. Its first quarter reflected growth in revenue and earnings.

Among holdings in which Fisher increased its stake was Sirius XM Radio (SIRI -4.43%). The heavily shorted Sirius has faced threats from automakers offering their own entertainment products, but they're still offering Sirius radio as well. Growing sales of vehicles is also a plus for Sirius, as is Pandora's recent decision to start charging its heaviest users. Meanwhile, Sirius has just taken on Pandora more directly, launching MySXM, which permits subscribers to customize radio stations. It has also won a major legal battle against Howard Stern.

Fisher reduced its stake in lots of companies, including Capstone Turbine (CPST) and Nokia (NOK -0.27%). Capstone is a smallish company, making low-emission microturbines used in power generation. Its top line has been growing by double digits over the past few years, and it's poised to profit from huge interest in shale oil, but it remains in the red. Still, it has recently announced a bunch of promising deals and some think the many folks short the stock will end up burned.

Once a market darling and now trading in penny-stock territory, Nokia has found success providing less developed economies with less expensive mobile phones. That strategy may not last, though, as smarter phones gain traction. Mean while, its sales in China have been shrinking significantly. Overall sales took a big hit, too, in Nokia's last quarter, though bulls still like its growing cash position and promising sales of its Lumia smartphones.

Finally, Fisher's biggest closed positions included Komatsu and Men's Wearhouse. Other closed positions of interest include Cliffs Natural Resources (CLF -0.49%). The stock, yielding about 3.4% after a massive 76% dividend cut, is down more than 70% over the past year, in part due to the struggling coal market. Some are bullish, though, given the company's debt reduction and a likely boost to business from a recovering housing market. The stock has fallen so far that some see it as attractive now.

We should never blindly copy any investor's moves, no matter how talented the investor. But it can be useful to keep an eye on what smart folks are doing. 13-F forms can be great places to find intriguing candidates for our portfolios.