[Nikkei Recap] Sept 11, 2026: Nikkei 225 Falls 1,259 Points to 64,011 as Oil Prices Surge and US Rates Climb

Hey everyone, Hirokichi here.

Tokyo stocks fell sharply on September 11, 2026, with the Nikkei 225 closing down 1,259.61 points (-1.93%) at 64,011.34. The selloff came from a “double punch” of surging oil prices, driven by escalating tensions in the Middle East, and rising US long-term interest rates. More than 80% of stocks on the Prime Market ended the day lower, making it a broadly negative session. Let’s look at what happened today, why the market fell this much, and which stocks were in the spotlight.

Today’s index moves

First, here’s where the major indexes closed.

*The exact Growth 250 close and the precise 4pm USD/JPY rate weren’t confirmed by data providers at the time of writing (mid-afternoon Japan time). These will be updated once confirmed.

As the table shows, the Nikkei briefly fell more than 2,000 points during the morning session before recovering slightly, still ending the day down 1.93%. TOPIX also fell, though less sharply at -0.65%. The Nikkei’s steeper decline compared to TOPIX reflects heavy selling in a handful of large, high-priced semiconductor-related stocks, which I’ll get into below.

What moved the market today

Today’s decline can be traced to three main factors.

(1) A sharp jump in oil prices. WTI crude futures rose $6.43 to $102.48 a barrel on September 10, an eighth straight day of gains, and briefly touched the $104 level in early Tokyo trading on the 11th. The trigger: President Trump signaled on September 9 that a resolution to the conflict with Iran wouldn’t come until after November’s US midterm elections, and reports emerged that Yemen’s Iran-backed Houthi rebels had seized the Red Sea port city of Mokha. With supply routes through both the Strait of Hormuz and the Red Sea now in question, resource-importing Japan faced a clear headwind. Oil-beneficiary stocks rallied, while broader selling hit companies exposed to higher input costs.

(2) Rising US long-term interest rates. The yield on 10-year US Treasuries climbed to around 4.9% on September 10, the highest level since October 2023. Higher rates raise the discount rate applied to future profits, which tends to weigh more heavily on high-P/E (price-to-earnings ratio) tech and semiconductor stocks.

(3) A weak close on Wall Street the previous day. The Dow fell 316.56 points (-0.6%) to 52,064.10 and the Nasdaq Composite dropped 171.62 points (-0.7%) to 26,081.73 on September 10. The Philadelphia Semiconductor Index (SOX) also tumbled, down 317.15 points to 11,614.17, and that weakness carried over into Tokyo trading on the 11th.

Stocks in the spotlight today, and why

Large, high-priced semiconductor names did most of the damage to the Nikkei’s point total today.

*Individual stock closing prices and percentage changes weren’t fully reflected by data providers at the time of writing (mid-afternoon Japan time). Only figures confirmed across multiple sources are shown; unconfirmed figures are marked “To be confirmed” rather than estimated.

Advantest (6857), Tokyo Electron (8035), and SoftBank Group (9984)

These three stocks dominated the ranking of biggest drags on the Nikkei 225 today. All three are “high-priced” stocks with outsized weight in the index, and all have exposure to semiconductor equipment or AI-related businesses. As noted above, the overnight slump in the US SOX semiconductor index, combined with valuation concerns for tech stocks as rates rose, triggered selling from the opening bell. Why did just three names move the index so much? Because the Nikkei 225 is a price-weighted index — stocks with higher share prices have a bigger impact on the index than stocks with lower prices, even for the same percentage move.

Kioxia Holdings (285A)

Memory chipmaker Kioxia was down roughly 7% from the previous close as of 3:34pm. Memory semiconductor makers’ earnings are highly sensitive to market conditions, making them frequent targets when rates rise. Given the stock’s recent strength on solid earnings, profit-taking likely amplified the move.

INPEX (1605)

On the flip side, resource stocks that benefit from higher oil prices saw buying. INPEX reportedly traded firmly as WTI crude futures extended their gains amid Middle East tensions, with peers like Japan Petroleum Exploration (1662) seeing similar interest. Today was a day that clearly split winners and losers along the oil-price fault line.

What this means for individual investors

If you’re dollar-cost averaging into index funds, there’s no need to react to a single day’s swing like today. In fact, a down day means your regular contribution buys more units at a lower price. Sticking to your usual pace matters more than reacting to headlines.

For those trading individual stocks over a shorter time horizon, days like today — when oil and interest rates both move against the market at once — tend to bring higher volatility, especially in large-cap names. Personally, I think it’s often better to wait for the dust to settle rather than force a “buy the dip” trade into this kind of cross-current.

What to watch going forward

Here are three things I’ll be watching in the days ahead.

(1) Oil prices. If Middle East tensions escalate further, oil could keep climbing, extending the headwind for resource-importing Japan. If things calm down, we could see a rebound after today’s sharp drop.

(2) US inflation data. The August US Consumer Price Index (CPI) report is coming up, and its outcome could further shift the direction of US long-term rates.

(3) The September quarterly settlement (SQ) for stock index futures and options. SQ weeks tend to bring extra volatility from supply-and-demand factors around expiring contracts, so it’s worth keeping an eye on unusually large swings.

Let’s keep at it, slow and steady. See you tomorrow!

* This article is for informational purposes only and does not recommend any specific investment. Please make investment decisions at your own responsibility.

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