VCG | Visual China Group | Getty Images HP shares have just had their best day in over two years, and Warren Buffett’s Berkshire Hathaway is nearly $ 650 million richer because of it. In a filing with the Securities and Exchange Commission late Wednesday, Berkshire revealed ownership of 121 million shares of HP, making it the largest shareholder in the PC and printer maker, surpassing Vanguard. Shares of HP rose 15% on Thursday after the revelation, boosting the value of Berkshire’s share to $ 4.85 billion from $ 4.2 billion. It was the biggest rally for HP since the first days of the pandemic in March 2020. The rapid market reaction to Berkshire’s stated share shows how much investors continue to pay attention to what Buffett says and does. HP is now Berkshire’s second largest technology company next to Apple. Berkshire owns more than $ 150 billion worth of iPhone maker shares. Buffett avoided high-tech stocks before his portfolio company began buying large quantities of Apple in 2016. Apple competes with HP in the PC market. Zoom Icon Arrows pointing outwards Sub-performance of HP before the unveiling of Berkshire CNBC While Apple remains a consistent producer, HP is more of a value share. Prior to Thursday, it was trading at about 8 times the future earnings, compared to a multiple of about 21 for the S&P 500 and 27 for Apple. And since the close of Wednesday, HP shares have risen 7.5% last year, following Apple’s 36% gain and a 10% rise for the S&P 500. Buffett’s investment comes at a time of uncertainty for the computer market. Sales of laptops and desktops have skyrocketed during the pandemic, boosting manufacturers including HP. However, some market analysts now believe that the growth of computer shipments will slow sharply next year and that the demand for computers has exceeded its peak. ATTENTION: HP shares rise after Berkshire Hathaway took 11.4% stake