A Look Into David Einhorn's Q4 Letter To Greenlight Investors

David Einhorn's Greenlight Capital released a letter to the fund's shareholders on Tuesday.

Here is a brief summary of some of the notable highlights.

Macy's: 'Math Might Make More Sense'

Shares of Macy's Inc. M were trading higher by nearly 4 percent early Tuesday afternoon after Greenlight Capital's letter confirmed the fund established a position in the retailer.

Related Link: These Three Stocks Destroyed David Einhorn's 2015

According to the letter, the fund established a position in Macy's at an average price of $45.69. The letter noted that with the stock trading south of $35.00 per share, the "math might make more sense" and shares are "cheap" at 5x EBITDA, 7x equity free cash flow, and less than 9x 2015 EPS.

Mylan: Medium-Term Upside

Greenlight Capital also disclosed a new position in Mylan NV MYL, which helped boost the stock higher by more than 1 percent by Tuesday afternoon.

Greenlight Capital pointed out that Mylan's stock has lost 29 percent during the first three quarters of 2015 and over 45 percent from its mid-year highs. However, the stock is expected to benefit over the medium-term from a competitor recall, an announced share repurchase, and board review of corporate governance complaints.

Selling Activity: Small Profits, Small Losses

Greenlight Capital said that a "pending cyclical downtown" prompted the fund to exit its stake in Applied Materials, Inc. AMAT for a "small loss."

A "small profit" was established in Bank of New York Mellon Corp BK as the market was giving the stock "too much credit for potential earnings leverage to multiple Fed rate hikes."

Greenlight Capital exited its position in London-listed Cairn Energy at £1.54 after initiating a small position in 2012 at £2.72.

After proving to be the top performer in 2014, Micron Technology, Inc. MU was the fund's "biggest loser" in 2015. Nevertheless, the fund exited its position at an average sale price of $22.14 after buying the stock at an average price of $19.93.

Finally, Greenlight Capital covered its short position in ARM Holdings plc (ADR) ARMH as the company proved to be more successful than expected in offsetting its problems by increasing the royalty rate it charged its clients.