U.S. stocks rebounded on Tuesday after artificial intelligence startup Anthropic PBC announced it is expanding its Claude chatbot into new areas and forming partnerships with software and service companies.

The S&P 500 index rose 0.8%, with nine of its 11 sectors closing higher, led by consumer discretionary, industrial, and information technology stocks. The Nasdaq 100 index climbed 1.1%.

A day after AI-driven "panic trading" hammered financial and software firms, Anthropic introduced new AI tools for its Claude Cowork agent software, designed to automate tasks in areas such as human resources, investment banking, and design. These tools were developed in collaboration with financial data provider FactSet Research Systems Inc. Shares of the company rose alongside those of Thomson Reuters and Adobe Inc.

Adam Crisafulli of Vital Knowledge wrote in a research note that Anthropic's focus on partnerships has eased market concerns by emphasizing how Claude can integrate with, rather than replace, existing systems.

"The message from Anthropic that 'we are here to help, not harm' has helped trigger a fairly healthy rebound in the software sector, which may be the most hated area in the entire market," he said.

Software stocks have been under particular scrutiny as investors have been selling for months due to concerns about the potentially disruptive impact of artificial intelligence.

MasterCard and Capital One Financial Corp., which fell sharply on Monday, also staged strong rebounds.