For much of the artificial intelligence boom, Nvidia Corp. (NVDA) has been the stock investors watched to gauge the health of the AI trade. Jim Cramer thinks that may no longer be enough.
"How did all of tech become hostage to SK Hynix!" the CNBC host wrote on X on Tuesday, highlighting what many investors have come to view SK hynix Inc. (SKHY) as one of the AI industry's biggest bottlenecks.
He followed up minutes later with another post, this one also commenting on Samsung Electronics Co., Ltd. (SSNLF) and Sandisk Corporation (SNDK): "And SK Hynix is hostage is leveraged to ridiculous leveraged ETFs!! We are about to be devoured by a three team parlay of Hynix, Samsung and SanDisk."
Popular leveraged ETFs for SK Hynix include ProShares Ultra SK hynix (SKHU), GraniteShares 2x Long SK Hynix Daily ETF (SKUU), and Leverage Shares 2X Long SK Hynix Daily ETF (SKHX).
While the comments were vintage Cramer—part observation, part hyperbole—they reflect a broader shift in how Wall Street views the AI supply chain.
SK Hynix's AI Role
The reason is high-bandwidth memory, or HBM.
Unlike traditional memory chips, HBM is designed to move massive amounts of data between memory and AI processors at extremely high speeds. It has become an essential component in Nvidia's latest AI accelerators, including its Blackwell platform.
SK Hynix has emerged as the leading supplier of these advanced memory chips, making its production capacity and demand outlook closely watched indicators for the broader AI market. Investors increasingly view the company's earnings and commentary as an early read on AI infrastructure spending and Nvidia's ability to meet soaring demand for its chips.
Why Nvidia Investors Should Watch
Although Nvidia remains the dominant force in AI computing, it cannot ship AI systems without sufficient HBM supply.
That has elevated SK Hynix from a memory manufacturer to one of the most important companies in the AI ecosystem. Strong HBM demand reinforces confidence in Nvidia's growth story, while any signs of supply constraints or softer orders can quickly ripple across semiconductor stocks.
It's also notable that Cramer's comments centered on SK Hynix, Samsung and SanDisk—not Micron Technology, Inc. (MU), another major U.S. memory maker that has been expanding its HBM business.
Whether intentional or not, the omission reflects how investors increasingly look to SK Hynix as the industry's primary AI memory barometer.
The Bigger Picture
Cramer's second post also pointed to another concern: market concentration.
By arguing that SK Hynix itself has become "hostage" to leveraged ETFs, he suggested trading flows—not just fundamentals—could be amplifying volatility in AI-related stocks. Combined with the market's growing reliance on a handful of memory suppliers, it underscores how critical the AI supply chain has become.
For Nvidia investors, the takeaway is straightforward: GPUs may remain the face of the AI boom, but the companies supplying the memory behind them are becoming just as important to watch.
