HP’sStock just experienced its highest day in over two years and Warren Buffett’s Berkshire Hathaway has almost $650million more.

filingThe SEC announced that Berkshire has acquired 121,000,000 shares of HP. It is now the largest shareholder in HP and the printer manufacturer, beating Vanguard.

On Thursday, HP shares surged 15% following disclosure. Berkshire’s stake jumped to $4.85Billion, from $4.2B. It marked the most significant rally by HP since March 2020’s pandemic.

Berkshire’s publicly disclosed stake has provoked a quick market reaction. It shows investors how attentive Buffett is to his words and actions. HP now holds the second largest tech stake in Berkshire, after Apple. Berkshire holds shares worth more than $150 billion in Apple’s iPhone manufacturer.

Buffett famously eschewed high-flying tech stocksHis holding company purchased large amounts of Apple before he started to hold them in 2016. AppleHP competes in the PC market.

Apple continues to grow, but HP remains more of a value stock. Before Thursday, it was trading at about 8 times forward earnings, compared to a multiple of about 21 for the S&P 500 and 27 for Apple. And as of Wednesday’s close, HP shares were up 7.5% over the past year, trailing Apple’s 36% gain and the 10% advance for the S&P 500.

The timing of Buffett’s investment is uncertain for the PC market. Manufacturers like HP have seen their sales rise during this pandemic. However, some analysts think that this is not the truth. PC shipment growth will slow drasticallyThe demand for computer systems is expected to rise in the following year.

WATCH: HP shares surge after Berkshire Hathaway takes 11.4% stake