Big Tech Stocks Drop; Palantir, AMD down 2%; Nvidia, Tesla, Amazon, Meta, Micron, Alphabet down 1%

Wall Street is looking at a negative start to September, with stock index futures down on Tuesday, as fresh uncertainty regarding tariffs hit investor sentiment.

S&P 500 futures fell 0.4%, Nasdaq 100 futures fell 0.6%, and Dow futures fell 0.4%.

Big tech stocks fell in premarket trading on Tuesday. Palantir, AMD fell 2%; Nvidia, Tesla, Amazon, Meta, Micron, Alphabet fell 1%.

A U.S. appeals court ruled late Friday that most of President Donald Trump's tariffs are illegal, determining the president exceeded his authority in his use of emergency powers to rewrite U.S. trade policy. However, the tariffs were allowed to stay in place for now while the case was sent back to a lower court for further proceedings.

However, the Trump administration is said to be pushing forward with trade negotiations even after the ruling, U.S. Trade Representative Jamieson Greer said Sunday.

Wall Street on Friday fell, weighed down by a slide in semiconductor stocks. Market participants also received a key inline inflation reading that did little to change expectations of a Federal Reserve interest rate cut in September.

"Trump is to deliver an Oval Office statement today. There are a number of topics the president may choose to address and a number of directions that may be taken on each of those topics. Uncertainty about policy has economic consequences—relevant as markets consider the next employment report on Friday," UBS' Paul Donovan said.

On the economic side, the August PMI Manufacturing Final and the ISM Manufacturing Index will land during market hours. The former is expected to come in at 53.3 and the latter at 49.0.

"U.S. data is mainly business sector sentiment (and some construction spending). Things like prices paid and employment intentions attract attention in the sentiment figures. However, the actual importance of these figures depends on whether the observer believes the survey responses accurately reflect reality," Donovan said.