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Top Stock Market Losers After the Opening Bell (Dec. 12, 2025): Broadcom Leads Decliners as AI Margin, Capex Fears Hit Tech

Top Stock Market Losers After the Opening Bell (Dec. 12, 2025): Broadcom Leads Decliners as AI Margin, Capex Fears Hit Tech

NEW YORK — Friday, Dec. 12, 2025 (updated around 9:46 a.m. ET): U.S. stocks opened mixed, with the tech-heavy Nasdaq under pressure while the Dow held up better—an early sign that investors are still rotating away from the most crowded parts of the “AI trade” and into other pockets of the market. AP News+1

The biggest early losers were concentrated in semiconductors and data-infrastructure names—led by Broadcom, which extended a sharp slide after management flagged pressure on gross margins tied to the company’s fast-growing AI systems business. Meanwhile, storage and memory names—some of 2025’s biggest winners—also fell in a bout of profit-taking. 

Below is a detailed look at the top losers after the opening bell on Dec. 12, 2025, what’s driving the moves, and what Wall Street is watching next.


Top losers in early U.S. trading

Biggest decliners in the S&P 500 (early Friday)

These were among the largest percentage decliners in the S&P 500 shortly after the open:

  • Broadcom (AVGO): down about 7.8%
  • SanDisk (SNDK): down about 3.8%
  • Micron Technology (MU): down about 3.4%
  • Western Digital (WDC): down about 2.5%
  • Synopsys (SNPS): down about 2.0%
  • GE Vernova (GEV): down about 1.9%
  • Seagate (STX): down about 1.9%
  • Teradyne (TER): down about 1.7%
  • Corning (GLW): down about 1.6%
  • Arista Networks (ANET): down about 1.6% 

Why this matters: This isn’t a random list—many of these names sit in the “picks-and-shovels” layer of AI infrastructure (chips, memory, storage, networking, chip design tools). When sentiment shifts on AI spending or profitability, these stocks often move together.

Biggest decliners in the Nasdaq 100 (early Friday)

The Nasdaq 100’s early losers skewed even more heavily toward AI-linked tech:

  • Broadcom (AVGO): down about 7.2%
  • Micron (MU): down about 3.0%
  • Shopify (SHOP): down about 1.8%
  • Synopsys (SNPS): down about 1.6%
  • Palantir (PLTR): down about 1.5% 

What’s driving the selloff: Broadcom’s margin warning jolts the AI complex

Broadcom (AVGO): “Great numbers” weren’t enough—investors focused on margins

Broadcom’s drop is the headline move. Even after projecting quarterly revenue above Wall Street expectations, the company told investors its gross margin would dip as AI revenue becomes a larger mix of its business. That is a key nuance: AI growth is strong, but it may not be as immediately profitable as the market wants.

Reuters reported that Broadcom expected first-quarter consolidated gross margin to be down ~100 basis points sequentially, “primarily reflecting a higher mix of AI revenue,” and highlighted investor sensitivity to profitability and concentration risk tied to a limited number of large AI customers. Reuters

Other closely watched Broadcom details feeding the debate:

  • Management discussed a $73 billion backlog expected to ship over the next 18 months. 
  • The company said AI semiconductor revenue (custom AI chips and networking for AI data centers) is expected to double to $8.2 billion in the fiscal first quarter. 
  • Broadcom forecast quarterly revenue of roughly $19.1 billion, above the analyst average cited by Reuters. 

The market’s takeaway in early trading: Broadcom is benefiting from AI demand, but it’s also being pulled deeper into the capital-intensive “systems” side—where margins can be thinner and execution risk is higher. Reuters+1


Why memory and storage names are sliding: profit-taking meets “AI ROI” anxiety

SanDisk (SNDK), Micron (MU), Western Digital (WDC), Seagate (STX)

After Broadcom’s warning, selling pressure spread to memory and storage stocks—names tightly linked to data center buildouts.

This group also has another trait: they’ve been some of the biggest winners of 2025, which can amplify pullbacks when momentum traders lock in gains. As of the data shown on Friday, SanDisk, Western Digital, Seagate, and Micron were among the top S&P 500 performers year-to-date. 

Early Friday’s declines included:

  • SanDisk (SNDK) down about 3.8%
  • Micron (MU) down about 3.4%
  • Western Digital (WDC) down about 2.5%
  • Seagate (STX) down about 1.9% 

The “AI spending payback” question is back—thanks in part to Oracle

A major undercurrent here is broader concern about how fast AI infrastructure spending turns into profits.

Oracle’s latest results and commentary earlier in the week helped revive that theme, with Reuters describing how Oracle’s weak forecasts and sharply higher spending expectations rekindled “AI bubble” chatter and triggered a tech selloff. Reuters+2Reuters+2

Reuters also noted that Oracle’s report weighed on a basket of AI-related stocks—including Nvidia, AMD, Micron, Broadcom, and Arm—as investors debated timelines for returns on AI investments. 


The chip-tool and “infrastructure software” pullback: Synopsys, Teradyne, KLA, Lam, Arista

The early losers list also included chip design software and semiconductor equipment:

  • Synopsys (SNPS) down about 2.0% in the S&P 500 snapshot
  • Teradyne (TER) down about 1.7%
  • KLA (KLAC) down about 1.5%
  • Lam Research (LRCX) down about 1.4%
  • Arista Networks (ANET) down about 1.6% 

These names are often treated as “downstream beneficiaries” of data-center capex. When investors get nervous that AI capex is outrunning near-term payoff—or that margins are compressing as companies scale—selling can ripple through the entire supply chain, from silicon to tools to networking. Reuters+2Reuters+2


GE Vernova (GEV): a different kind of loser—downgrade jitters after a huge run

Not every decliner was tech.

GE Vernova (GEV) fell roughly 1.9% in early S&P 500 trading. 

One catalyst in the news cycle: Barron’s reported that GE Vernova had been downgraded to Hold from Buy by Seaportafter an “epic run,” with the analyst arguing the risk/reward now looked more balanced—even as many analysts remained positive. Barron’s

GE Vernova also sits at the intersection of two mega-themes—grid buildout and power demand—which has made it a market darling in 2025. A pullback on downgrade chatter fits the pattern of “sell the news” behavior in high-flying, widely owned stocks. Barron’s+1


Broader market setup: Nasdaq down, Dow steadier as “AI bubble” talk persists

Friday’s early tape reflected a familiar split:

  • Tech/AI stocks weaker
  • Broader market steadier, with money rotating into other sectors

Investopedia pointed to mixed futures after the Dow and S&P 500 closed at record highs on Thursday, while tech remained under pressure amid ongoing AI-bubble concerns. 

The Associated Press similarly described a market where AI-linked names weighed on the Nasdaq while the broader market showed resilience, with gains in other corners of the market offsetting weakness in mega-cap tech. 

Reuters’ analysis added an important nuance: even as Oracle’s stumble bruised the AI trade, some investors argued it was more company-specific than a death knell for AI—and short sellers hadn’t meaningfully piled into the largest AI beneficiaries, a sign that many pros remain wary of betting on a full unwind. 


What to watch later today: Nasdaq 100 reshuffle headline risk after the close

Even though today’s story is “AI losers after the bell,” one after-the-close event could inject extra volatility—especially in Nasdaq-linked names.

Reuters reported that Nasdaq’s annual Nasdaq 100 reshuffle announcement is expected after the market close on Friday, with changes effective Dec. 22. The report highlighted Strategy (MSTR) as a debated name, with some analysts questioning whether it qualifies for inclusion based on business-model considerations. 

That matters because index reshuffles can trigger large passive flows—a key source of short-term price swings even when fundamentals haven’t changed. 


Bottom line: today’s “top losers” tell a clear story about investor priorities

The early action on Dec. 12, 2025 shows investors raising the bar for AI winners yet again:

  1. Growth is not enough—markets want clarity on margins and payback.
  2. AI-adjacent stocks that have surged in 2025 are vulnerable to fast profit-taking.
  3. The broader market can still hold up—even when headline tech names slide—if leadership rotates. 

Reminder: Stock prices can move quickly, especially in the first hour of trading. This article is a market-news snapshot, not investment advice.

Stock Market Today

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