Microsoft adds about $450 billion in market value in a single day, reaching a record one-day gain for a U.S. company, according to multiple outlets. The surge is reported as Microsoft’s largest one-day jump in market capitalization to date, with one report citing a gain of roughly $450 billion and another describing it as a near-$450 billion increase. The companies’ trading move pushes Microsoft to a new high in terms of market capitalization, reflecting a sharp repricing by investors over the course of the day. Sources describe the event as a record-setting gain in market value, emphasizing both the scale of the increase and that it represents the largest one-day gain attributed to a U.S. company. The reports do not indicate a single, specific fundamental driver in the information provided, but they concur on the core facts: the size of the one-day gain and its record status. The figures are presented in market-value terms (market capitalization), measured over the same day’s trading session.