Applied Materials' stock price slumped by double digits after the semiconductor equipment maker reported a project revenue decline amid tariff worries in China.

Ten large-cap stocks, including CRWV, COHR & AMZN, were the worst performers last week. Weak results, downgrades, and FTC probe may be the reasons.

Analysts wonder if China’s recent “overspending” on chip equipment is coming to a halt — and if the company is losing market share to rivals.

Beijing E-Town Semiconductor Technologies , a semiconductor equipment firm backed by Beijing's government, on Wednesday said it has sued U.S. chip equipment supplier Applied Materials over alleged trade secrets infringement.

Applied Materials (AMAT) stock falls after the company issued guidance that fell short of Wall Street's expectations. Warren Buffett's Berkshire Hathaway (BRK-B, BRK-A) added to its stakes in homebuilder stocks Lennar (LEN) and DR Horton (DHI).

Applied Materials forecast fourth-quarter revenue below estimates on Thursday, citing bumpy demand from clients amid economic uncertainty, sending its shares down 11% in extended trading. U.S. President Donald Trump's ongoing global tariff negotiations,

Shares of technology companies declined as a tepid outlook from one major chip-equipment manufacturer cast a pall on the semiconductor sub-sector. Shares of Applied Materials plunged after the maker of semiconductor manufacturing equipment forecast growth short of Wall Street expectations.

CNBC's Kristina Partisinevelos joins 'Squawk on the Street' to discuss the latest earnings from Applied Materials.