Stock watch: Nvidia, Samsung, AMD, and Intel updates (December 26)

A major breakthrough in the semiconductor supply chain has sent ripples through the market today. Samsung Electronics has secured a critical approval from Nvidia (NVDA) for its next-generation HBM4 memory chips, solidifying a strategic alliance that is reshaping the competitive landscape for AI hardware. While Samsung shares rallied sharply, the news offers complex implications for market leader Nvidia and key rival AMD.

The catalyst: Samsung wins “Rubin” approval

The headline driving the sector is Samsung’s confirmation as a supplier for Nvidia’s upcoming Rubin AI processors. According to recent reports, Samsung’s HBM4 memory chips have passed rigorous testing for Nvidia’s 2026 AI accelerators.

• Production timeline: Mass production is scheduled to begin in February 2026 at Samsung’s Pyeongtaek facility.

• Market reaction: Samsung shares surged 5.3% following the announcement, reflecting investor optimism about the company closing the gap with rival SK Hynix.

• Strategic depth: This deal deepens a 25-year partnership between the two tech giants, moving beyond standard components to critical infrastructure for future AI factories.

Nvidia stock: Stability amidst future growth

While the news is fundamentally bullish for Nvidia’s long-term supply chain security, the stock is currently consolidating after a massive yearly run. The HBM4 approval ensures Nvidia will have the necessary memory bandwidth to power its Rubin architecture, maintaining its dominance in the AI accelerator market.

Technical snapshot:

• Current price: ~$188.61 USD

• Daily movement: A slight pullback of 0.32%, trading within a tight range of $186.59 – $188.72.

• Key levels: The stock is holding above its 50-day moving average of $185.85, indicating short-term stability. With a market cap of approximately $4.59 trillion, Nvidia remains the heavyweight to beat, though it currently sits below its yearly high of $212.19.

Image: Perplexity AMD stock: The challenger holds ground

Advanced Micro Devices (AMD) is not directly involved in the specific HBM4 deal between Samsung and Nvidia, but the company remains a central figure in the semiconductor rally. AMD has shown significant strength recently, posting a weekly gain of 8.55%.

The Samsung connection: It is important to note that Samsung is not exclusive to Nvidia. Samsung already supplies HBM3E memory to AMD, and strategic ties exist regarding AMD’s MI350 chips.

Price action:

• Recent close: $215.04 USD

• Current level: Hovering near $213.13 USD.

Intel stock: Nvidia rejects 18A foundry node

Nvidia has reportedly decided not to move forward with Intel’s 18A manufacturing process for its AI chips.

• The news: Despite a recent strategic partnership where Nvidia took a $5 billion stake in Intel to co-develop CPUs, the manufacturing side of the deal has hit a wall. Reports indicate Nvidia evaluated Intel’s “18A” node but found the yields or performance insufficient to replace its reliance on TSMC.

• Why it matters: This is a major vote of confidence for TSMC and a setback for Intel’s goal to become a “national champion” foundry. Investors had hoped Nvidia would diversify its supply chain to Intel’s US factories; the rejection suggests TSMC’s technology remains the undisputed leader for high-performance AI silicon.

• Stock impact: Intel (INTC) shares slipped 3% on the news, while Nvidia remains stable, as the decision removes the risk of transitioning to an unproven manufacturing process.

Sector analysis: Correlation and competition

The relationship between Nvidia and AMD remains a focal point for investors. Data indicates a moderate positive correlation (0.51) between the two stocks. While they often move in tandem due to broader sector sentiment, their individual drivers are diverging.

• Nvidia is focusing on maintaining an unassailable lead with the Rubin architecture and secure supply chains (Samsung/SK Hynix).

• AMD is positioning itself as the viable alternative, challenging Nvidia’s market share. While Nvidia has grown faster over the last 12 months, AMD’s recent weekly performance suggests traders are rotating capital to catch “lagging” plays in the AI trade.

The approval of Samsung’s HBM4 chips for Nvidia’s Rubin platform is a significant de-risking event for the AI industry’s 2026 roadmap. It boosts Samsung’s standing against SK Hynix, secures supply for Nvidia, and sets a high bar for performance that AMD will need to match. Investors should watch the $185.85 support level for NVDA and whether AMD can sustain its momentum above $210.

Is the stock market open Friday?

Yes, the stock markets relevant to your article (Nvidia, AMD, Intel, and Samsung) are open today, Friday, December 26, 2025.

Here is the specific breakdown for the exchanges you are tracking:

• US Market (Nvidia, AMD, Intel): OPEN

  • The NYSE and Nasdaq are operating on a full regular schedule today (9:30 AM – 4:00 PM ET). They are not observing Boxing Day.

• South Korea (Samsung): OPEN

  • The Korean Stock Exchange (KOSPI) is open for trading today.

• Other Markets (Boxing Day): CLOSED

  • Major markets in the UK (LSE), Canada (TSX), Australia, and Europe are closed today for the Boxing Day holiday.

Disclaimer: The content of this article is for informational purposes only and should not be construed as investment advice. We do not endorse any specific investment strategies or make recommendations regarding the purchase or sale of any securities.