U.S. equities added about $1.1 trillion in market capitalisation on Monday, according to trading data compiled after the close. The one-day jump was led by large-capitalisation technology companies that reported stronger-than-expected earnings and by continued momentum in artificial-intelligence-linked names. The rally in stock valuations coincides with a resurgence in corporate dealmaking. Global mergers and acquisitions have reached $2.6 trillion so far this year, the highest January-to-July total since 2021, Dealogic data cited by Reuters show. Although the number of transactions is 16 % lower than a year earlier, their combined value is 28 % higher, powered by U.S. megadeals exceeding $10 billion and a $40 billion funding round for OpenAI. Bankers say executives are using a more stable regulatory backdrop and the urgency to secure AI capabilities to justify larger transactions and renewed risk-taking. The United States accounts for more than half of all global M&A activity, while private-equity firms are also returning to the market with multi-billion-dollar bids.