Jack Pitcher

A few are based in the U.S., like SanDisk.

And this ETF is a very concentrated bet on four or five of the biggest memory stocks.

So it's less risky than only owning one of them and lets investors easily get exposure.

There's also some evidence of bigger investors buying this, like hedge funds, based on the ticket sizes.

But another kind of unique part about this one is they're seeing a lot of overseas retail interest that they expect is from South Korean investors.

Retail trading is really popular in South Korea.

And now that a couple of the biggest Korean companies that manufacture memory have become hot stock market plays in the U.S., it's become a really popular ETF for Korean investors to trade.

Hey, listeners, it's Saturday, February 28th.

I'm Jack Pitcher for The Wall Street Journal, and this is What's News in Markets, our look at the biggest stock moves of the week and the news that drove them.

Let's get to it.

AI was in focus once again this week, and it feels like investors don't know what to make of the rapid advancements in artificial intelligence models.

AI optimism has been one of the biggest drivers of market gains the past few years.

But in 2026, traders are thinking more about what threats it could pose.

That tension came to a head on Monday, when everyone on Wall Street was talking about a viral blog post from a small investment research firm that imagined an AI doomsday scenario for white-collar workers.

Stock indexes sold off sharply Monday, and analysts pointed to the memo as a prime culprit.

By the end of the week, indexes had posted modest declines.

The S&P 500 fell 0.4%, while the Nasdaq was 1% lower, and the Dow dropped 1.3%.

A winner has emerged in the Warner Bros.

sweepstakes, and investors on both sides are actually happy.

Netflix had previously reached an agreement to buy Warner's movie and TV studios, as well as the HBO Max streaming service.