Warren Buffett lost $1.06 billion after the plunge in IBM shares on October 20.

IBM stock fell $15.05 at the open, and Warren Buffett held about 70.2 million shares as of June 30, according to the most recent SEC filings. That means the sharp decline cost him $1.06 billion.

Warren Buffett lost $1.06 billion after the plunge in IBM shares

In April, after a prior weak earnings report, Warren Buffet told CNBC he had not “soured” on IBM, that he had bought more stock this year and that he had not sold a share.

IBM stock was recently the third-largest holding in Warren Buffett’s portfolio, trailing only Wells Fargo and Coca-Cola.

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