Greenlight Capital, the hedge fund of billionaire investor David Einhorn, saw the value of its equity holdings decline to $5.47 billion from $6.03 billion over the final three months of the year, according to the latest regulatory filings. Among the moves the fund made, the Apple Inc. holding was slashed to 6.3 million shares from 11.7 million shares; the entire 12.4 million-share stake in Micron Technology Inc. was sold off, as was the 5 million share stake in Applied Materials Inc. and the 4 million share stake in Bank of New York Mellon Corp. ; and the General Motors Co.