Activist Investors Show Their Hands in Latest 13F Filings

Activist investors like Carl Icahn and Daniel Loeb try to keep their targets a secret until they're ready to strike, but intrepid investors can scour their 13F filings for clues on what they're planning.

And aside from their activist investing, it's worth keeping an eye on what's in and out of favor with the big hedge fund managers, since their involvement often affects a stock's price.

The latest 13F filings, for the quarter that ended March 31, just became available this week and are required by the U.S. Securities and Exchange Commission (SEC) of any money manager with $100 million in qualifying assets. And they show that most of the best-known activist investors were very busy in the year's first quarter.

Let's look at some general trends first, then we'll check on the latest moves of some of the top activist investors.

In the big picture, top investors suddenly got very hot on Verizon Communications Inc. (NYSE: VZ). The quarter showed a remarkable 52.85% increase in ownership among those required to file 13F forms. Verizon is now held by 1,631 13F filers, the ninth highest.

Some of the big names that bought Verizon in the first quarter were Warren Buffett, Dan Loeb, and John Paulson.

Another stock that caught the eye of several top hedge fund managers was international cable company Liberty Global Plc (Nasdaq: LBTYK). Buffett's Berkshire Hathaway Inc. (NYSE: BRK.A, BRK.B) added 7.35 million of the K shares and an equal number of the A shares (Nasdaq: LBTYA).

David Einhorn's Greenlight Capital also increased his stake in Liberty Global by 66%, buying nearly 1.25 million shares. Daniel Loeb's Third Point LLC tripled his stake with a purchase of 3.6 million shares of Liberty. And George Soros bought 1.38 million shares of LBTYK.

Meanwhile, top investors were dumping troubled General Motors Co. (NYSE: GM) stock. Berkshire dumped 10 million shares of GM, and Jana Partners nearly 8 million. Loeb sold all of his 17 million shares.

Now let's take a closer look at what some of the top activist investors were doing in the March quarter…