Powell's Caution Hits Stocks, But Micron's AI Boom Signals More Rally Ahead (Sept 2025)
Powell's Caution Spooks Wall Street, But Micron's AI Boom and a Korean Rally Tell a Different Story
Last updated: September 25, 2025 | Reading time: 8 minutes
Fed Chair Jerome Powell threw a wet blanket on the market rally with another dose of caution. While his words sent the major indices tumbling, a much more powerful narrative was unfolding beneath the surface: a stunning earnings report from Micron Technology. It was proof that the AI revolution is far from over. Across the Pacific, another story of strength emerged as South Korea's KOSPI index continued its record-breaking rally, capturing the attention of global investors.
This post dives deep into the short-term impact of Powell's jitters, the long-term signal from Micron's AI demand, and the unique bull case for the South Korean market. Plus, a special look at a high-risk, high-reward "Japju" for the adventurous investor.
🎯 Key Takeaways
✅ Micron's Blowout Quarter: Driven by data center demand, Micron smashed revenue and earnings estimates, proving that demand for AI-related semiconductors remains red-hot.
✅ South Korea's Breakout: The KOSPI index is on a tear, fueled by the government's "Corporate Value-up Program" and a powerful semiconductor-led rally.
✅ Speculative Stock of the Day: Zeta Global (ZETA), an AI-powered marketing cloud company, presents an interesting case with high growth potential and significant risk.
Quick Answer: Despite short-term market anxiety from Powell's comments, Micron's stellar earnings reaffirmed the fundamental strength of the AI theme, providing a strong tailwind for tech stocks and, notably, the semiconductor-led rally in South Korea.
📉 1. Powell's Remarks Rattle a Pricey Market
"I want to be cautious now." With those words, Jerome Powell sent a shiver through Wall Street. The Nasdaq dropped nearly 1%, with the S&P 500 and Dow following suit. Powell noted that the stock market seems somewhat overvalued, and he's not wrong. The S&P 500's Price-to-Earnings (P/E) ratio is now hovering above 23, nearing the highs seen during the pandemic bubble. His comments were enough to trigger latent fears of a market correction. But does this signal the end of the bull run? Not necessarily.
🚀 2. The Real Story: Micron Proves AI's Power with Numbers
Behind the market noise, Micron delivered the real signal. Revenue jumped 46% year-over-year, and Earnings Per Share (EPS) skyrocketed by an astonishing 156%. Most critically, their data center business unit reported its best results ever. This is concrete proof of the voracious demand for memory chips needed to train and run AI models. As Micron's CEO boldly stated, they have secured a "unique position to capitalize on the coming AI opportunities." Micron's success is a powerful positive indicator not just for Nvidia, but for the entire semiconductor supply chain—especially for key memory players in South Korea like Samsung and SK Hynix.
| Metric | Result |
|---|---|
| Revenue | +46% YoY |
| EPS | +156.8% YoY |
| Gross Margin | 45.7% (vs 44.3% exp.) |
| Guidance | Beat (Positive) |
🇰🇷 3. The Global Bridge: South Korea's Hot Rally
While U.S. markets catch their breath, South Korea's KOSPI is writing a new story. This rally is powered by two strong engines. First, the government-led "Corporate Value-up Program" is creating expectations that the long-standing "Korea Discount" (the tendency for Korean stocks to be undervalued) will finally be resolved. Second is the emergence of clear, leading sectors, summarized by new investor slang like "Geum-Ban-Ji" (Financials, Semiconductors, Holding Companies). Micron's strong results only add fuel to this fire, reinforcing the bull case for Korea's semiconductor sector. Analysts believe these are structural changes, not just a fleeting trend, giving the KOSPI the stamina for another leg up.
💡 4. Today's "Japju": A Look at Zeta Global Holdings (ZETA)
In Korean investor slang, a "Japju" (잡주) is a speculative stock—financially unproven but with explosive growth potential. Today's feature is Zeta Global (ZETA). This company combines three of the hottest buzzwords in tech: AI, Cloud, and Marketing. It offers an AI-powered platform that provides customized marketing solutions for its clients.
- The Bull Case: Revenue growth is accelerating, and the company is successfully attracting "Super-scale" clients (those spending over $1 million annually). The total addressable market for AI-driven marketing is massive.
- The Bear Case: The company is still unprofitable. It faces immense competition from giants like Adobe, Salesforce, and Oracle. As a small-cap stock (around $5 billion), it's inherently volatile.
ZETA is a high-risk, high-reward play on the future of AI in the marketing industry. It's not for the faint of heart, but it's an interesting name to watch.
❓ Frequently Asked Questions
Q: Why did stocks fall after Powell's speech?
A: Powell expressed caution about cutting interest rates too soon due to ongoing risks. This reduced investor hopes for imminent rate cuts, causing a sell-off in a market that was already considered expensive.
Q: Are Micron's earnings good for Samsung and SK Hynix?
A: Yes, very good. Micron's record data center sales confirm that the global demand for memory chips for AI is extremely strong. As two of the world's largest memory chip makers, Samsung and SK Hynix are direct beneficiaries of this trend.
Q: What is the "Corporate Value-up Program" in Korea?
A: It's a government initiative encouraging Korean companies to improve shareholder returns through better governance, higher dividends, and stock buybacks. The goal is to close the "Korea Discount" and make the market more attractive to investors.
📚 Related Guides
• The 2025 Guide to South Korean ETFs (EWY)• How to Invest in the Semiconductor Cycle
• How Fed Policy Actually Impacts Your Stock Portfolio
💭 My Analysis
In my experience, markets often overreact to short-term macro news but ultimately follow long-term technological shifts. Powell's comments are the 'noise'; Micron's earnings are the 'signal'. The AI infrastructure build-out is a multi-year trend that is only just beginning. This acts as a powerful, long-term tailwind for both U.S. tech leaders and their critical component suppliers in South Korea.
The KOSPI rally is particularly interesting because it has a dual engine: the global AI demand and the domestic policy momentum from the "Value-up Program." This makes the South Korean market a compelling alternative for portfolio diversification right now. I believe investors would be wise to focus on the signal of technological demand rather than the noise of central bank commentary.
