Stock Market Today: A choppy stock day; a tweet on China; inflation cools; Nvidia, Tesla, Palantir

Updated at 11:30 am ET

It's a bit of a choppy morning on Wall Street. Stocks opened lower after the president tweeted that China had "totally violated its agreement with us." 

Breadth was weak, too, with 80% of S&P 500 stocks on the decline. At the same time, the index is well off the day's lows. As the heat map shows, it's a mixed day.

In the upper right corner is Costco  (COST) . The warehouse-club retailer's shares are higher following yesterday's earnings and revenue report, which beat expectations. Although the reaction was muted in after-hours trading, the shares are up 3% on strong volume.

This shouldn't be a surprise to members of TheStreet Pro. Our Bob Lang wrote Tuesday that Costco shares were primed to hit new highs following the earnings report.

Costco is also viewed positively within TheStreet Pro's Portfolio, and although we don't currently own it there, it's a stock we would like to buy on pullbacks.

Another stock that's up is the data-analytics-software provider Palantir  (PLTR) . That's a stock favored by TheStreet Pro's Stephen "Sarge" Guilfoyle. It's trading just below all-time highs. 

The New York Times reports that "Trump Taps Palantir to Compile Data on Americans" as part of his March executive order requiring data sharing across government agencies.

At the same time, Sarge reports that he's taken some profits in Palantir and other tech names. He still likes the stock, but is a trader at heart. 

You won't go broke taking a profit!

Stock Market Today

The weekend is almost here! We're expected to have a lovely one in Colorado. I hope yours will be similarly wonderful.

I wasn't planning to start the day with a tweet, but let's do it.

BREAKING: President Trump says China has “totally violated its agreement with us.”

In an apparent breakdown of the trade deal, Trump says “so much for being Mr. Nice Guy.”

Did the US-China trade deal just collapse? pic.twitter.com/bEssPlOQIL— The Kobeissi Letter (@KobeissiLetter) May 30, 2025

This has prompted what was a fairly flat market to drop today. As I write this, S&P futures are down 33 points. The Nasdaq is lower by 130, and crude oil is now down 52 cents after being about 70 cents higher.

Here's an overnight chart of the S&P 500.

It's hard to tell now if we're in for a wild ride today or whether traders are having a level of fatigue and will watch before making further reactions.

In the meantime, we just got today's big economic news. The PCE Index, short for Personal Consumption Expenditures Index, is a measure of inflation. The Bureau of Economic Analysis reports that April's PCE increased by $47.8 billion, or 0.2%, which was 2.1% higher than a year earlier but lower than the 2.3% expectation. 

In other words, inflation is cooling.

The PCE is the Federal Reserve's preferred benchmark for prices as it determines interest-rate policy.

Premarket most actives include Nvidia  (NVDA) , which had been down as much 1.4% but is now 0.4% lower.

Jim Cramer attributes the dip to "meme money," which, to be honest, is driving so much of our markets these days.

I was hoping there would be less meme money in Nvidia but i was wrong. Witness the stock in premarket is down 87 cents. That's just small motivated shareholders knocking it down. Probably no more than 35,000 shares sold took the biggest stock down a huge percentage— Jim Cramer (@jimcramer) May 30, 2025

And hey, while we're at it, let's talk Tesla  (TSLA) . Well, Elon Musk, actually. Today is expected to be the billionaire's last day in office as his official time with Doge comes to an end. Expect a news conference later this afternoon from the Oval Office with Musk and President Trump.

However, the New York Times reports today that Musk used heavy amounts of drugs while on the campaign trail last fall with Trump. In fact, the paper reports, his use of ketamine was so great that he suffered from bladder problems, a known effect of chronic use. 

As Musk integrates himself back into Tesla leadership, shareholders will likely question him on this and it could become an issue.