I will also upload a briefing after compiling it.

It's better to put it up here ㅎㅎ

🇰🇷🇺🇸 Korea-US Stock Market Weekly Briefing

Reference Date: Saturday, September 12, 2026
Korean and US Markets: Based on closing prices on September 11th

This week's key point is that while the Korean stock market rebounded this week centered around semiconductors and AI, the 'high interest rate + high oil price' combination, with the US 10-year yield approaching 5% and Brent exceeding $100, has emerged as the biggest risk factor again.

KOSPI rose from 6,687.21 last week to 6,909.91, an increase of about +3.33%, KOSPI200 rose from 1,051.52 to about 1,080, an increase of +2.7%, and KOSDAQ rose from 813.50 to 820.64, an increase of +0.88%. However, on Friday alone, KOSPI fell -1.76%, with foreigners net selling about 2.29 trillion won, failing to hold the 7,000 mark in the middle of the week. (Seoul Economic Daily)

1. 🇰🇷 Weekly Analysis of the Korean Stock Market

This Week's Most Important Changes

Last week:

Korea's Strong Fundamentals vs. U.S. Interest Rate Burden

was the case, but this week:

Semiconductor·AI Repurchasing → KOSPI Breaks Through 7,000
→ Oil Prices $100+ / US10Y Approaching 5%
→ Foreign Investors Taking Profits

has changed to this flow.

Therefore, it's not Korea's own issue, but rather a structure where the global discount rate is again blocking the upper levels.

2. Market Breadth·Volatility

This week's market saw improved risk appetite from Monday to Wednesday, but strong selling focused on large-cap stocks on Friday.

On Friday, foreigners sold 2.29 trillion won net on KOSPI, institutions sold 1.22 trillion won net, and individuals bought 1.87 trillion won net. In particular, foreigners' net selling of SK Hynix was about 1.08 trillion won, and institutional selling was concentrated in Samsung Electronics. (The Korea Times)

However, since the beginning of the month, foreigners have not completely withdrawn from the entire Korean stock market. According to Reuters/LSEG data, foreigners made net inflows of about 1.1 billion dollars into Korean stocks in early September, and reallocation to Asian AI·tech stocks is continuing. (Reuters)

Assessment

Weekly Foreign Investor Direction = 🟡 Mixed

• AI·Semiconductor Buying Return: 🟢

• Friday Large-Scale Selling: 🔴

• Korean Won Strength: 🟢

• Long-term Rates·Oil Prices: 🔴

In other words, it is not yet at the stage to judge as structural foreign investor withdrawal.

3. Derivatives Market

In the observable KOSPI200 futures, contango was maintained relative to the spot price during the week. The September 10 futures were around 1,082.15 level, and the divergence from the spot price did not turn into extreme backwardation. (英为财情 Investing.com)

However, we were unable to reliably cross-verify the final supply and demand, open interest, and put-call ratio by investor type after the quarterly expiration this week on a consistent basis.

Therefore, I will not arbitrarily estimate the derivative market numbers.

Next week, too, the combination of Spot + Futures + OI is the most important judgment criterion.

Spot + / Futures + / OI↑ → New Long
Spot - / Futures - / OI↑ → New Short

.

4. 🇰🇷 Korea Market Quant

This week's model weights are:

Trend 20% + Momentum 15% + Supply and Demand 15% + Breadth 10% + Sector RS 10% + Earnings/News 10% + Macro 10% + Cross-Asset 5% + Volatility 5%

.

Korea Market Quant = 67 / 100

B / Bullish Momentum but Macro Headwinds Expanding

Last week's score of 65 rose to 67.

The improvement in stock prices and semiconductor momentum slightly outweighed the deterioration in interest rates and oil prices.

5. Korea Sector Quant Ranking

The most notable feature this week is the resurgence of semiconductors and AI.

6. 🟢 Semiconductor & AI - Leading Players Confirmed Again

This week's KOSPI surge on Monday was largely driven by semiconductors.

On September 7th, Samsung Electronics rose approximately +5.7%, and SK Hynix surged +8.3%, lifting the KOSPI by +4.6%. (Barron's)

Furthermore, the renewed collaboration between OpenAI and Samsung Electronics on next-generation chips and AI infrastructure was confirmed. The structural growth story of AI memory demand continues. (Reuters)

The total scale of shareholder returns for Samsung Electronics and SK Hynix this year has also expanded to over 130 trillion won. This signifies that the AI cycle is being converted into actual cash flow. (Reuters)

Semiconductor Quant

Key Judgement

Long-term 🟢 / Short-term 🟡

There are few problems with fundamentals.

The problem is US10Y ≈ 5%.

7. ⚡ Power Equipment & Nuclear Power - Structural Score Increase

The Korean government reports that the domestic electricity demand could increase by 25~30GW due to the rise in AI data centers and semiconductor factories. This is equivalent to the output of approximately 20 nuclear power plants. There have also been reports from Reuters that the government is considering expanding nuclear power (Reuters)

Therefore, the AI investment path is:

GPU → HBM → Data center → Transformer·Transmission and distribution → Nuclear/Gas

Expanding.

Quant

Power equipment 79 / Nuclear power & energy infrastructure 74

However, as interest rates rise, valuation expansion is limited.

8. Finance — Quant 76

Currently, financial stocks have characteristics opposite to growth stocks.

Short-term and long-term interest rate hikes
→ Positive for NIM
→ Negative for economic conditions and default risk

.

This week, global fund flows also saw inflows into the technology and finance sectors (Reuters)

As long as high interest rates persist, Korean financial stocks are likely to maintain their relative strength.

9. Elliott Wave — KOSPI

This week's wave provided some significant information.

The last key structure was:

5,593 → 7,216 → 6,408

.

This week, it rose again to 7,171 and then fell to 6,910.

Therefore, the current situation is:

Scenario A — New Rise 43%

Possible count:

5,593 → 7,216 = 1st wave
7,216 → 6,408 = 2nd wave
6,408 → present = initial stage of 3rd wave

.

However, if it is a 3rd wave, the following conditions are necessary.

Confirmation Conditions

7,172 → 7,216 breakout

.

And after the breakthrough, trading volume and foreign buying should increase.

If these conditions are met, it could raise the probability of an upward 3rd wave to more than 50%.

10. NEoWave — Still More Conservative Than Elliott

From Neil's perspective, the overlap in recent movements is still too large.

6,400 → 7,171 → 6,900 occurred within a very short period of time.

For a normal impulse trend to strengthen:

Price adjustment ↓
Time adjustment ↑
higher-low repetition

is needed.

NEoWave

The probability of a new uptrend has increased from 38 → 41% compared to last week.

The best structure is not a surge next week, but:

Time adjustment between 6,800~7,000 → Decrease in volatility → Breakthrough of 7,200

.

11. 🇺🇸 US Stock Market

Although each index rebounded by about +0.9~1% on Friday, all indices declined for the week. Russell2000 was the weakest at -2.4%. (AP News)

US Market Quant

61/100 — Neutral+

Lower than last week's 67.

The US is currently:

AI Performance 🟢
Economy 🟢
Oil Prices 🔴
Inflation 🔴
Interest Rates 🔴🔴

.

12. 🇺🇸 CPI/PPI — This Week's Decisive Macro Changes

PPI

PPI matched the consensus on a monthly basis, but the annual growth rate rose to 5.4%. The surge in energy prices (+4.2%) played a significant role. (Reuters)

CPI

Headlines matched consensus but Core CPI MoM +0.3% exceeded the +0.2% consensus. (Reuters)

13. Consumer Sentiment Deteriorated

University of Michigan consumer sentiment:

51.7 → 47.8

fell sharply, significantly undershooting the Reuters consensus of 51.0.

One-year inflation expectations surged from 4.0% to 4.6%. (Reuters)

Therefore, the US faces a very uncomfortable combination.

Growth slowdown signs + high inflation expectations

In other words, the risk of stagflation has risen slightly.

14. Macro Surprise Score

Scoring from a stock market perspective:

Global Macro Surprise

-22 / 100 🔴

Korea's fundamentals and US macro are moving in opposite directions.

15. 🇺🇸 US Treasuries — The Most Important Warning Sign

Friday:

• US 2Y approximately 4.64%

• US 10Y approximately 4.97%

• 30Y is close to mid-5%

The US 10-year rose to 4.9915% intraday. (Reuters)

Previous week:

US10Y 4.78%

→ This week:

4.97%

Approximately +19bp.

This is the most important number this week.

The 4.8% that users previously viewed as a risk level has already been breached.

Therefore, the new risk level is:

⚠️ US10Y 5.0%

.

If 5% is continuously breached, the discount rate burden for long-term growth stocks such as AI, robotics, and power equipment will increase by one level.

16. 🇰🇷 Korea Government Bonds Also Surge

Korea's 10-year bond:

9/4 4.361% → 9/11 4.542%

Rose approximately +18bp. (Investing.com Korean)

The 3-year also exceeded 4%.

September 11 morning:

• 2Y 3.928%

• 3Y 4.018%

• 10Y 4.553%

It was. (Yonhap News)

In other words, South Korea is not free from the shock of high US interest rates.

17. 💱 Exchange Rate — Unexpectedly Good Signal

The won/dollar was around 1,346 won on September 11th, still relatively low. (Investing.com)

Therefore, the worst-case scenario of interest rate surge → dollar strength → won plunge has not yet materialized.

This is an important buffer for the Korean market.

18. 🛢️ Energy — Current Biggest Tail Risk

Friday:

• Brent $104.61

• WTI $100.05

.

Both rose 8~10% week-on-week. (Reuters)

The IEA projected a significant reduction in global oil supply this year due to supply disruptions in the Middle East, and Saudi supply has fallen to its lowest level in over 30 years. (Reuters)

Therefore, the risk line is now:

Brent

• <$95 🟢

• $95~100 🟠

• >$100 🔴

• >$110 🔴🔴

.

Currently, it is already in the 🔴 zone.

19. 🥇 Gold·Silver·Copper

Gold and silver fell weekly due to rising interest rates despite geopolitical uncertainty. (Reuters)

Gold↓ + Bond Yields↑

means the market's core is now "**inflation & tightening**" rather than "fear".

20. 🌽 Grains

Corn, wheat, and soybeans' **September 11th benchmark closing prices and weekly returns were not reliably cross-verified.**

Therefore, we will not estimate prices.

However, currently, **crude oil, diesel, and transportation costs** are putting much greater inflationary pressure than food inflation.

21. ₿ Bitcoin / Ethereum

Bitcoin adjusted to around **$77K** on Friday. Strong CPI and interest rate hike expectations weighed on liquidity-sensitive assets. (Investor's Business Daily)

Ethereum also shows similar Risk-on sensitivity, but we couldn't secure reliable benchmark weekly closing prices and returns for this search, so we won't display the numbers.

Crypto Signal

🟡 / Liquidity Risk-on Weakening

22. ⭐ Cross-Asset Dashboard

Cross-Asset Quant = 47 / 100

Last week 55 → 47

For the first time, it clearly drops below 50.

This is the most important Quant change this week.

23. Why did KOSPI rise anyway?

There is currently a very interesting discrepancy.

Equity

KOSPI +3.3%

Macro

US10Y 4.97%
Brent $105

It is.

The reason is that the EPS growth rate of Korean AI and semiconductors is too strong.

Korea's exports from January to August this year already exceeded last year's annual record high, reaching $709.4 billion, and semiconductor exports increased by about +170% compared to the same period last year, accounting for 41% of total exports. (Reuters)

In short:

EPS growth rate > Discount rate increase

This is still maintained.

However, if the US10Y rises above 5%, this balance may change.

24. Next Week's Biggest Event - FOMC

The FOMC will be held on September 15-16.

The market is currently reflecting a probability of about 87-92% for a 25bp rate hike. (Barron's)

The current benchmark interest rate is 3.50-3.75%.

If the rate is hiked:

3.75-4.00%

It will become.

Therefore, this time, the hike itself is less important than the dot plot and Warsh's remarks.

25. Fed Scenarios

🟢 Dovish Hike

A 25bp rate hike, but:

• Limited further hikes

• Energy shock is temporary

• Data dependent

Emphasis

→ US10Y decline
→ SOX rebound
→ Very favorable for Korean semiconductors

🟡 Hawkish Hike

25bp + possibility of further hikes

→ US10Y remains at 5%
→ KOSPI high volatility box

🔴 Very Hawkish

25bp + suggestion of additional hikes in October/December

→ US10Y >5.1%
→ DXY rise
→ Pressure on growth stock valuation

It is.

26. BOJ is also very important

The BOJ is also likely to raise rates by 25bp next week, with the benchmark interest rate potentially rising from 1.00% to 1.25%. (Reuters)

Therefore, next week:

Fed tightening + BOJ tightening

May occur simultaneously.

This is an important variable for global leverage and yen carry trades.

Be sure to check high beta stocks such as Korean semiconductors and robots.

27. Key Events in Korea Next Week

Next week, domestic import/export prices and August PPI are scheduled.

Since oil prices have exceeded $100, the Korean PPI is becoming increasingly important. (EconomicsAPI)

28. KOSPI Quant Scenario for Next Week

Recalculating with this week's data.

The probability of a rise is lowered from 37 → 31%, and the possibility of a fall is raised from 21 → 25%.

Base Scenario

High Volatility Box Range 44%

.

29. Next Week Technical Map

30. Risk Matrix

31. Final Dashboard

This Week's Final Judgment

This week, the Korean stock market actually improved. KOSPI +3.3%, semiconductor RS recovery, Korea's highest ever exports, KRW in the 1,340 won range, and continued AI demand are being confirmed. Korea's exports from January to August have already exceeded last year's annual record high, with a semiconductor export growth rate of about 170%. (Reuters)

However, the most important change this week is not stock prices but the fact that Cross-Asset Quant has dropped from 55 to 47.

**US10Y 4.97%

• Korea10Y 4.54%

• Brent $104.6

• WTI $100

• Fed Hike Probability ~90%**

This combination is definitely risky. (Reuters)

Therefore, the most accurate description of the current market is:

“Korean corporate earnings are strong, but the global discount rate has risen to a dangerous level”

.

Next week, it is **more appropriate to watch the US 10-year Treasury note before the KOSPI**.

The 5 most important signals I will be watching are

1. Whether US10Y settles at 5.0%

2. Whether Brent breaks through $105~$110

3. Whether the Fed suggests further rate hikes after a 25bp increase

4. Whether foreigners start buying Samsung Electronics and SK Hynix again

5. Whether KOSPI breaks through 7,216 with trading volume

.

Especially, **if US10Y falls below 4.8% despite the Fed hike, KRW stays below 1,380 won, and foreigners simultaneously switch to net buying in both spot and futures markets**, Elliott's new bullish 1-2-3 scenario probability **can be increased from 43% to over 50%**.

Conversely, **if US10Y settles above 5% and Brent approaches $110 while foreigners simultaneously sell spot and futures**, even if KOSPI stays around 7,000, the market risk rating **should be lowered to C+ level from B**.

Currently, it is a market where **we need to observe "how long interest rates and oil prices will allow Korea's strong EPS" rather than following trends**.