Greenlight Capital filed an amended 13F yesterday that disclosed the detail of the fund’s investment in Micron Technology, Inc. (NASDAQ:MU). While the hedge fund bought Micron in Q3, it did not disclose the investment in the mandatory 13f filed on November 14. According to the new filing David Einhorn holds 23 million shares of the semiconductor company which would amount to a 2.2% stake.

David Einhorn

David Einhorn’s confidentiality request

Apparently Greenlight Capital requested confidentiality treatment for this particular investment, a relaxation that expired on November 21. David Einhorn presented Micron Technology, Inc. (NASDAQ:MU) as his best idea at the Robin Hood Investors Conference on November 21, so it is possible that he was saving the disclosure until after the conference. This represents one of Greenlight’s largest investments – the stake amounts to $402 million and is the fund’s fourth largest holding on the 13F filing.

Take a look at David Einhorn’s thesis on Micron Technology here.

Most concentrated holding

It was not just David Einhorn who bought Micron Technology, Inc. (NASDAQ:MU), apparently a lot of hedge funds were buying the company in the third quarter. According to Goldman Sachs’ Hedge Fund Trend Monitor, Micron Technology has now become one of the most concentrated hedge fund holdings.

The report from Goldman Sachs Group Inc (NYSE:GS) estimated that hedge funds owned nearly 21% of the equity cap at the end of third quarter, a total of 82 hedge funds are reporting the company on their 3Q2013 13F filings. This is a major increase from the previous ownership in 14% of equity at the end of 2Q2013. Meanwhile short interest in Micron stood at 9% of float at the end of Q3.

Other hedge funds who are major owners of the semiconductor company include Seth Klarman’s Baupost Group, which owns 64 million shares of the company after buying 22 million shares in the third quarter. Andreas Halvorsen’s Viking Global holds 37.4 million shares, out of which roughly 30 million were bought in last quarter. Rob Citrone’s Discovery Capital owns 22.9 million shares.

Better seasonal trends for memory chips

Analysts at Susquehanna Research are not as excited about the company as these famous hedge fund managers. In a research note released on November 21, the firm maintained its Neutral rating on the company. Mehdi Hosseini notes that Micron is in a position to benefit from better DRAM ASP market, both due to seasonal trends and issues with supply at other manufacturers. Hosseini says that supply of DRAM chips will be hampered by the fire that broke out at the plants of its Korean competitor, Hynix. In light of this development, Hosseini increased the price target but did not see any intrinsic factor that warranted higher growth.

Shares of Micron Technology, Inc. (NASDAQ:MU) have gained 218% YTD, making its rich shareholders even richer.