📉 KOSPI Sheds 8.77% in a Week as Oil Jumps 14% — The Two Forces That Rattled Markets

Korean stocks had a brutal third week of July: the KOSPI plunged 8.77% in a single week to fall back below 6,800, while over the same stretch international oil prices jumped more than 14%. Stocks and oil moved in opposite directions for two intertwined reasons — a tech-stock pullback driven by the “AI bubble” debate, and a spike in oil prices out of the Strait of Hormuz. Here is why the two trends diverged, laid out in numbers. 📊

TL;DR

The KOSPI closed the week at 6,820.60 (-8.77% vs. the prior week) and the KOSDAQ at 791.84 (-5.44%), a sharp correction for Korean equities.
WTI crude surged 14.07% on the week to $81.49 a barrel, driven by Strait of Hormuz risk.
Oil-driven inflation fears and a stronger dollar combined to chill risk appetite for the week.

📉 The Week in Equities — KOSPI Down 8.77%, Back Below 6,800

Korean equities saw large caps and smaller names slide together, widening the correction. The KOSPI index closed at 6,820.60, down 655.34 points or 8.77% from the prior week. The KOSDAQ also fell to 791.84, off 45.59 points or 5.44%.

The steepest single-day drop came on July 16. That day alone the KOSPI plunged 463.81 points, or 6.37%, to close at 6,820.60. The so-called “AI bubble” narrative took hold, and a rush of selling in semiconductors and tech stocks was the direct trigger for the slide.

U.S. markets were weak in lockstep. The tech-heavy Nasdaq Composite fell hardest, down 2.90% to 25,520.24; the S&P 500 dropped 1.59% to 7,454.74; and the Dow Jones Industrial Average slipped 0.93% to 52,146.39. With Korean and U.S. tech stocks correcting at the same time, risk-off sentiment stood out.

🛢️ Why Oil Jumped 14% — the Hormuz Risk

The most striking move in commodities this week was the surge in oil. West Texas Intermediate (WTI) crude climbed to $81.49 a barrel, up $10.05, or 14.07%, from the prior week.

The trigger was Middle East geopolitical risk. Oil spiked immediately after U.S. President Donald Trump, on July 13 local time, floated reimposing a naval blockade of the Strait of Hormuz and charging transit tolls. By some tallies, that day’s single-session gain was the largest in about six years, since May 2020. The Strait of Hormuz is a chokepoint of global oil transport, with roughly 21 million barrels of crude passing through each day — so tension there feeds straight into prices.

💵 How Currencies, Rates, and Safe Havens Moved

Even as equities fell, market indicators pointed in different directions. The won/dollar exchange rate traded at 1,489.4, down 9.66 won from the prior week and back below 1,500, though still high enough to keep pressure on the FX market.

In bonds, the yield on three-year Korean Treasury bonds rose 0.089 percentage point to 3.852%. With equities weak but bond yields rising, the signal is that wariness about inflation and monetary policy still lingers. The U.S. 10-year Treasury yield, by contrast, eased slightly to 4.547% — and with stocks weakening even as yields fell, worries about a slowing economy grew.

In FX, the dollar was firmly stronger. The dollar index, which tracks the greenback against major currencies, rose 0.61 point to 100.73. Gold, a classic safe haven, actually fell 2.64% to $4,012.19 an ounce, and Bitcoin held near $64,039 in a soft, range-bound session.

🔍 Why Stocks and Oil Diverged — the Week’s Structure

The key to reading this week’s market lies in why oil and stocks moved in opposite directions. The oil spike reignited inflation fears, which in turn pushed investors to trim risk assets such as equities.

It is also worth noting that stocks failed to rebound even as U.S. Treasury yields eased. On rates alone the backdrop could have been supportive, but two burdens — a stronger dollar and rising energy prices — weighed on sentiment. On top of that, the “AI over-investment” bubble debate hit the semiconductor and tech names that had led the market, and Korean equities reflected that burden especially hard.

📝 The Takeaway

This week’s market saw an “AI bubble” tech pullback collide with a Hormuz-driven oil spike, leaving the KOSPI with a hefty 8.77% weekly correction. Oil jumped more than 14%, reviving inflation fears, and a stronger dollar deepened the flight from risk.

Three things are worth watching from here. First, whether tension around the Strait of Hormuz escalates will shape the path for oil and inflation. Second, whether the “AI bubble” debate spreads into a deeper correction in semiconductor and tech stocks, or proves a passing wobble, is the key question. Third, in the monetary environment reshaped by the Monetary Policy Board’s July 16 rate hike, how the exchange rate and bond yields move bears watching. Rather than any single indicator, it is worth watching how these threads interlock.

※ This article is for informational purposes only and is not investment advice.

📉 The Week in Equities — KOSPI Down 8.77%, Back Below 6,800

🛢️ Why Oil Jumped 14% — the Hormuz Risk

💵 How Currencies, Rates, and Safe Havens Moved

🔍 Why Stocks and Oil Diverged — the Week’s Structure

📝 The Takeaway

Sources