Ken Griffin, Citadel Raise Exposure to Monolithic Power Systems, Inc. (MPWR), and AMC Entertainment Holdings Inc (AMC)

Ken Griffin‘s Citadel Investment Group has disclosed, in two filings with the SEC, moves made into Monolithic Power Systems, Inc. (NASDAQ:MPWR), and AMC Entertainment Holdings Inc (NYSE:AMC). The fund revealed increasing its stake in Monolithic Power Systems to around 1.93 million shares, from 1.70 held at the end of September.

Ken Griffin with computers

In its latest 13F, Citadel also disclosed holding a total of 5,000 shares of  Monolithic Power Systems, Inc. (NASDAQ:MPWR), held under the “Call” and “Put” options. Following the increase, the fund holds 5.0% of the company’s outstanding stock. Monolithic is engaged in production and sale of analog and mixed-signal semiconductors. In the third quarter, it posted a net revenue of $57.7 million, up by 15.6% on the year.  The stock of Monolithic Power Systems, Inc. (NASDAQ:MPWR) gained 52% since the beginning of the year.

Phill Gross and Robert Atchinson‘s Adage Capital Management is also a shareholder of Monolithic Power Systems, Inc. (NASDAQ:MPWR), disclosing ownership of some 1.7 million shares, worth $52.2 million in its latest 13F.

In the second filing, Citadel revealed ownership of 7.7% of AMC Entertainment Holdings Inc (NYSE:AMC)’s Class A outstanding stock. The fund holds a total of more than 1.6 million shares of the company, boosting the stake from approximately 936,300 shares owned at the end of September, together with 5,100 shares held under “Call” and “Put.”

The stock of AMC Entertainment Holdings Inc (NYSE:AMC) rose by 35.3% year-to-date, sporting a P/E of nearly 18. Paulson & Co, led by John Paulson held the largest position in AMC Entertainment Holdings Inc (NYSE:AMC), as revealed in the latest round of 13F filings. Its stake amasses 4.95 million shares, with a reported value of $338.8 million.

Earlier this month, Citadel  boosted its stake in Trulia Inc (NYSE:TRLA). The fund currently holds 2.5 million shares, up from 49,600 shares, and 90,600 shares held under options revealed in its latest 13F.

Disclosure: none