Why are SK Hynix and Samsung stocks crashing more than 10% today?

SK Hynix and Samsung stock plunged more than 10% in Seoul on Tuesday as investors reassessed the risks surrounding the artificial intelligence boom and China’s accelerating semiconductor ambitions.

The memory-chip maker fell as much as 11.1% on July 28, while Samsung Electronics lost nearly 10%.

The KOSPI dropped 7.41%, triggering temporary restrictions on programme trading as its two largest chip stocks intensified the market decline.

SK Hynix’s US-listed shares had already closed Monday at $143.02, below their $149 offering price.

The weakness carried into Asian trading, but the rout looks more like a sentiment and valuation reset than evidence that high-bandwidth memory demand has suddenly collapsed.

AI financing fears shake the market’s strongest trade

SK Hynix has become a major beneficiary of the AI infrastructure boom because it supplies advanced HBM used alongside Nvidia accelerators.

Samsung has also gained from expectations that rising demand for memory and foundry services will improve earnings.

That success left both companies vulnerable when investors questioned whether the scale and financing of data-centre investment can be sustained.

Nvidia fell nearly 5% in Monday’s US session after reports that it could provide about $250 billion in financing guarantees for an OpenAI data-centre project.

Low-cost Chinese open-source models added uncertainty by suggesting that some AI workloads may require less advanced computing power than previously assumed.

There is no clear evidence that HBM orders have collapsed, but elevated expectations mean even strong demand may no longer be enough to support premium valuations.

Kiwoom Securities analyst Han Ji-young told Reuters that semiconductor shares had fallen sharply despite stronger-than-expected results from Samsung and Alphabet.

His warning highlighted the market’s new standard: investors now want reassurance on future AI spending, pricing and order visibility, not merely solid quarterly numbers.

CXMT turns China’s chip ambitions into a valuation risk

China supplied another pressure point. CXMT closed 466% above its IPO price after its Shanghai debut, demonstrating strong domestic support for a national memory champion.

Reports that a state-backed Chinese company had begun producing immersion deep-ultraviolet lithography equipment added to fears that local manufacturers could gain access to better chipmaking tools.

CXMT remains behind SK Hynix and Samsung in advanced HBM technology.

Its listing nevertheless provides capital to expand conventional DRAM capacity, improve manufacturing processes and reduce China’s reliance on imported memory.

Mirae Asset Securities analysts noted that investors were less concerned about CXMT’s current earnings than its potential for “accelerated capacity expansion” and technological development after the IPO.

The threat does not require CXMT to overtake either Korean producer in HBM immediately.

Faster growth in commodity DRAM could pressure prices, weaken Samsung’s conventional-memory margins and persuade investors to apply lower valuation multiples across the sector.