Of the 15 largest stock investments, IBM is the only one that has lost value (page 15). Simultaneously, it looks like the largest cost based investment (next to BAC, which is unlisted in the table). Yet, he does not seem to address that position in any of his writing. I wonder what he thinks of the company.
On page 7 in the 2011 annual report, Buffett wrote that, as a long-term shareholder, he wished for the IBM stock to languish throughout the following 5 years. The reason was that IBM was planning large share repurchases, and the lower the stock price the higher the percentage of shares retired, and the larger Berkshire's stake would be in the long run.