Greenlight Capital’s David Einhorn is one of the most prolific investors on the scene right now, and his Q4 2013 13F filing provides some insights into where his strategy is headed this year. Last quarter, Einhorn mixed it up a bit, buying and selling a fair amount. He also left a number of his positions unchanged, including iBillionaire Index (NYSE:BILLION) constituents Apple Inc. (NASDAQ:AAPL) and General Motors Company (NYSE:GM).

David Einhorn Greenlight Capital

David Einhorn’s New Acquisitions

David Einhorn’s activity includes a total of nine new acquisitions, which now represent a combined 20.75% of his fund. Eight of them are below 2%, which makes his acquisition of 47 million shares of Micron Technology, Inc. (NASDAQ:MU) even more impressive.

The roughly $1 billion stake was announced before the filing, causing a stir as the news leaked before the transaction was actually closed. Since February 2013, Micron’s share price has increased +221.37%, including a +34.36% jump since Einhorn’s November purchase. The company is a leader in the highly-profitable semiconductor industry and last January reported quarterly revenues of $4.04 billion.

Micron is now David Einhorn’s second largest allocation, composing 14.22% of his fund and sitting just behind Apple. It also holds the seventh spot on the iBillionaire Index and is in the portfolios Seth Klarman, Richard Chilton and Ray Dalio.

Here are all of David Einhorn’s new Q4 positions:

David Einhorn’s Increased Positions

Apart from the newcomers, David Einhorn solidified his stakes in several key companies. In total, the billionaire increased six positions, which now collectively comprise 8.12% of his fund, up from 7.48% the quarter before.

David Einhorn’s Decreased Positions

It wasn’t all shopping for Einhorn last quarter. The hedge fund manager decreased positions in 10 companies, downsizing his total stake in them from 31.85% to 18.55%.

His most significant sale was of NCR Corporation (NYSE:NCR). Previously Einhorn’s sixth largest allocation, it has now fallen to number 15. He also scaled back his exposure in iBillionaire Index holding CIGNA Corporation (NYSE:CI).

Sold Out

Only one company was dropped from David Einhorn’s portfolio in Q4: U.S. homebuilder NVR, Inc. (NYSE:NVR). It previously represented 0.37% of the billionaire’s fund.