Published: October 18, 2026 at 11:31 AM
Weekly Market Memory
Weekly Market Memory
1. Weekly Summary
Defensive sectors, energy and long-dated bonds cushioned the sell-off. September CPI came in at 3.7%, above the 3.6% forecast, and PPI rose 6.3% year-over-year, the largest gain since 2022, yet the 10-year yield fell from 5.24% to 5.10%. Money leaving equities flowed into bonds, lifting TLT +2.65%. Consumer staples XLP +5.02%, health care XLV +3.45% and utilities XLU +1.93% absorbed funds sold out of tech. Brent rose to $109.86 (+4.91%) and WTI to $101.41 (+10.41%), and energy XLE gained +4.86%. JPMorgan's raised net interest income guidance and a 72% jump in Goldman Sachs equities trading revenue helped financials XLF hold a +1.44% gain. The value-heavy Dow closed higher at +0.67%.
Three negatives converged in one week. China's CXMT announcement of high-density memory on 10-12 rattled memory stocks, and the CPI beat on 10-14 added to discount-rate pressure. The same day, CoreWeave's 2032 notes yielded around 15% and its 5-year CDS topped 1,000bp, shifting the AI infrastructure debate from profitability to credit. The semiconductor ETF SMH fell for eight straight sessions, the longest streak since 2008, and ended the week -10.53%. Tech XLK fell -7.70% and the Nasdaq -4.48%, the worst week since June. The shock was bigger in Asia. The KOSPI dropped -7.57% on 10-15, triggering a circuit breaker, and finished the week -14.46% (5,668.05). The KOSDAQ fell -10.93%, EWY -15.12% and the Nikkei -5.37%. The VIX rose from 14.84 to 19.99, and the tech volatility index VXN stands at 27.13.
The first inflection point is the Asian open on Monday, 10-19. On 10-16 the KOSPI rebounded +2.05% and foreign investors turned net buyers for the first time in nine sessions, but US trading the same day saw EWY -3.70% and SMH -3.41%. Whether markets absorb that gap on Monday and hold the weekly low of 5,450.81 will decide whether a second leg down follows. Next come capex guidance from big tech earnings and the 10-27~28 FOMC. Eight straight down days in semiconductors is unusually oversold, leaving room for a technical bounce. But if CoreWeave bond concerns spread to high yield, the bounce will be short-lived.
2. Last Week's Outlook Review
| Prior-week outlook | Actual result | Verdict |
|---|---|---|
| If September CPI beats expectations, the 10-year retests the weekly high of 5.36%, defensive rotation firms up, and corrections in growth and small caps deepen | CPI beat at 3.7%. Defensives (XLP +5.02%, XLV +3.45%) and the growth and small-cap correction (Nasdaq -4.48%, Russell 2000 -3.05%) played out as forecast. The 10-year instead fell to 5.10%, so there was no retest | Partially correct |
| If TSMC and ASML reaffirm demand, SMH rebounds; if credit concerns spread to AI infrastructure, the 600 level breaks | Chip stocks fell despite TSMC's net income +68.7%. As credit concerns spread to CoreWeave, SMH closed at 539.79 (-10.53%), well below 600 | Correct |
| The KOSPI reopening gap and foreign investor flows will decide whether the 6,600 level holds | Foreign selling continued and the KOSPI closed at 5,668.05 (-14.46%), breaking 6,600. USD/KRW fell to KRW 1,329.60 (-1.00%), a stronger won, yet selling persisted, so identifying flows as the key variable was right. The size of the drop far exceeded the expected range | Partially correct |
| If defensive rotation continues, index record highs and narrowing market breadth go together | Rotation strengthened (XLP, XLE and XLV +3.5~5.0%). The index did not hit records but slipped, with the S&P 500 -1.95% | Partially correct |
| Risk: a CPI beat pushes long-term yields up to 5.4~5.5% | CPI beat, but the 10-year fell to 5.10% and the 30-year to 5.44% | Missed |
| Risk: Brent above $110 would combine an inflation re-acceleration with rate-hike pressure | Brent $109.86 (weekly high $110.00), WTI $101.41 (+10.41%). PPI at 6.3% confirmed the re-acceleration in inflation | Correct |
| Risk: an AI credit crunch transmits semiconductor losses to the broader index | CoreWeave bonds at 15%-plus and CDS at 1,000bp. SMH -10.53% spread to the Nasdaq -4.48% and S&P 500 -1.95% | Correct |
| Risk: debate over Fed independence pushes the 30-year above 5.60% | The 30-year fell to 5.44% (-2.86%) | Missed |
| Risk: trade clash before the Russia sanctions law takes effect and the US-China tariff truce expires | All that can be confirmed is that the oil-price drop from the Russian diesel deal faded on 10-16. The tariff truce expiry (11-10) has not yet arrived | Cannot assess |
3. Portfolio Drift & Risk
Weekly Portfolio Drift
Last week all four asset classes rose together, but this week stocks and bonds moved in opposite directions again. That the 10-year fell 14bp despite CPI at 3.7% and PPI at 6.3% means bonds regained their role as a haven. Energy moved independently of the equity decline as oil rose on Hormuz disruptions. Gold slipped -0.67% even in a risk-off phase. After the 10-14 CPI print, real yields and the dollar rose and gold dropped -1.49% in a day, then recovered +1.79% on 10-15. Within equities, the gap between SPY -1.97% and QQQ -5.52% widened to 3.5 percentage points, showing the decline concentrated in tech.
Risk Analysis
Weekly Detail by Asset Class
| Asset class | Representative ticker | Weekly return | Notes |
|---|---|---|---|
| Equities | SPY | -1.97% | QQQ -5.52%. Against the Nasdaq -4.48%, the Dow +0.67% split value from growth |
| Fixed Income | TLT | +2.65% | 10-year 5.10% (-2.67%), 30-year 5.44%. Rose on safe-haven buying despite the CPI beat |
| Gold | GLD | -0.67% | Gold futures $4,181.10 (-0.83%). Recovered after the 10-14 plunge. Silver SLV -5.97% |
| Energy | XLE | +4.86% | Brent $109.86 (+4.91%), WTI $101.41 (+10.41%). No. 2 sector |
Risk Indicator Interpretation
| Indicator | Value | Meaning / context |
|---|---|---|
| VIX (fear index) | 19.99 (prior week 14.84, weekly high 22.31) | Out of the normal 12~18 range and just short of 20. VXN 27.13 (+32.02%) shows anxiety concentrated in tech |
| 10Y Treasury yield | 5.10% (prior week 5.24%, weekly high 5.33%) | Fell despite hotter inflation data. Interpreted as a decline driven by safe-haven demand rather than fading expectations of rate hikes |
| Max weekly drawdown | S&P 500 -1.95% (10-09 7,811.54 → 10-16 7,659.44) | Nasdaq -4.48%, SMH -10.53%, KOSPI -14.46% (intraday weekly low 5,450.81) |
| 2-week cumulative S&P | -0.82% (7,722.72 → 7,659.44) | Gave back all of W41's +1.15% this week |
| Regime | risk_off | VIX just under 20, eight straight down days in semiconductors, defensive sectors leading, long-dated bonds rising. HYG -0.48% shows credit overall still holding |
4. Sector Performance
5. Week at a Glance
| Date | Market summary | S&P 500 | NASDAQ | VIX | WTI | Regime |
|---|---|---|---|---|---|---|
| 10-12 (Mon) | Semiconductors fell on the CXMT memory announcement and money moved into energy and consumer staples. KOSPI -3.65%, US bond market closed | 7,807.24 (-0.06%) | 27,245.90 (-0.44%) | 15.21 | $93.74 | neutral |
| 10-13 (Tue) | US flat as bank earnings were mixed. KOSPI -5.46% on KRW 4.5 trillion of net foreign selling | 7,805.45 (-0.02%) | 27,204.38 (-0.15%) | 15.27 | $94.14 | neutral |
| 10-14 (Wed) | SMH -3.98% on the September CPI beat at 3.7% and the CoreWeave bond plunge. Only health care and consumer staples rose | 7,718.94 (-1.11%) | 26,692.87 (-1.88%) | 16.87 | $95.09 | risk_off |
| 10-15 (Thu) | Dow +1.08% rebound as the 10-year fell to 5.09% despite PPI at 6.3%. KOSPI -7.57% with a circuit breaker | 7,744.06 (+0.33%) | 26,713.03 (+0.08%) | 16.46 | $97.97 | neutral |
| 10-16 (Fri) | Semiconductors fell for an eighth straight session and the Nasdaq had its worst week since June. WTI broke $100. KOSPI rebounded +2.05% | 7,659.44 (-1.09%) | 26,140.03 (-2.15%) | 19.99 | $101.41 | risk_off |
| 10-17 (Sat) | Weekend closure. 10-16 close carried over | 7,659.44 | 26,140.03 | 19.99 | $101.41 | risk_off |
| 10-18 (Sun) | Weekend closure. 10-16 close carried over | 7,659.44 | 26,140.03 | 19.99 | $101.41 | risk_off |
6. Trading Signal Changes
Start-of-Week vs End-of-Week Signal Comparison
| ETF | Asset class | Start-of-week entry condition | End-of-week entry condition | Change | End-of-week Trail buffer |
|---|---|---|---|---|---|
| SPY | Core | Met | Met | → | 27.65% |
| QQQ | Core | Met | Met | → | 23.04% |
| XLK | Core | Met | Met | → | 20.27% |
| SMH | Theme | Not met | Not met | → | 0.35% |
| AIPO | Theme | Not met | Not met | → (dropped out 10-12) | -5.93% |
| BOTZ | Theme | Not met | Not met | → | -0.79% |
| EWY | Theme | Not met | Not met | → | -11.89% |
| ROKT | Theme | Not met | Not met | → | -6.88% |
| XLE | Theme | Met | Met | → | 19.93% |
| XLV | Theme | Met | Met | → | 18.80% |
| CPER | Commodities | Not met | Met | ↑ | 10.13% |
| DBB | Commodities | Not met | Not met | → | 7.47% |
| GLD | Safe haven | Not met | Not met | → | -2.46% |
| TLT | Safe haven | Not met | Not met | → | 7.61% |
| Individual stock | Start-of-week entry condition | End-of-week entry condition | Change | End-of-week Trail buffer |
|---|---|---|---|---|
| AAPL | Met | Met | → | 28.65% |
| MSFT | Met | Met | → | 25.99% |
| NVDA | Met | Met | → | 17.99% |
| META | Met | Met | → | 20.96% |
| MU | Met | Met | → | 0.05% |
| TSLA | Met | Not met | ↓ | 8.24% |
| AMZN | Not met | Not met | → | 17.05% |
| GOOG | Not met | Not met | → (met midweek, then dropped out) | 13.40% |
| AVGO | Not met | Not met | → | -3.36% |
| LLY | Not met | Met | ↑ | 27.24% |
| SPCX | — | — | — | -5.28% |
Rebalancing Actions
Exit
After last week's exit, the Trail buffer shrank from 7.97% to 0.35% and reached the stop line. CXMT competition and AI infrastructure credit concerns combined to prevent a rebound even after TSMC's strong results. After eight straight down days, we will not hold any weight until a re-entry signal appears, even if a technical bounce occurs.
Trim, hold off on new entry
The entry condition held, but the Trail buffer collapsed from 8.82% to 0.05%. Of the five discussions, the three with a Trail buffer below 4% were SKIP, and the remaining two REDUCE calls also ended in losses. We will trim the position and revisit after SK hynix earnings on 10-27 and the FOMC.
Accumulate, split at half size
The entry condition and the 18.80% Trail buffer held. It is the key beneficiary of defensive rotation, and large constituents were supported as LLY entered anew on 10-15. All three discussions called for half-size entries, so we will build the position in tranches on pullbacks near the MA50.
Hold
The 19.93% Trail buffer is ample. WTI rose +10.41% on the week, so the risk of chasing is high. We will keep the weight unchanged without adding, and watch whether Brent settles at $110 and Hormuz traffic volumes.
Hold
All three kept their entry conditions. However, the XLK Trail buffer shrank 6 percentage points in a week, from 26.61% to 20.27%. We will defer adding new weight until VXN stabilizes below 27 and big tech capex guidance is confirmed.
Watch
The entry condition was newly met on 10-15 and the Trail buffer is 10.13%. Copper futures were weak at -1.66% on the week, and slowing AI capex weighs on the copper demand thesis. As this is the first signal, approach only with a small position.
Watch
The entry condition is not met, but the Trail buffer widened from 4.71% to 7.61%, leaving the danger zone. If the 10-year falls further from 5.10%, an entry signal gets closer. With a risk of yields retracing before the FOMC, we will wait for the signal.
Exit
TSLA dropped out of its entry condition on 10-13 and AIPO on 10-12. AIPO's Trail buffer fell to -5.93%, vindicating last week's six SKIP calls in discussions.
Maintain exit
The Trail buffer deepened to -11.89%. Foreign investors turned net buyers on 10-16, but institutions sold KRW 682.4 billion, so buying did not broaden.
Watch
The Trail buffer is recovering from -5.60% to -2.46%. The direction of real yields will be set at the FOMC, so we will wait for a signal until then.
Weekly Signal Events
- New entry conditions met: GOOG (10-13), CPER (10-15), LLY (10-15)
- Entry conditions lost: AIPO (10-12), TSLA (10-13), GOOG (10-14)
- Entered Trail danger zone: MU (10-14, 2.86%, 10-16 0.05%), SMH (10-14, 4.06%, 10-16 0.35%)
- Fell below the stop line (Trail buffer turned below 0%): SPCX (10-13), AIPO (10-14), AVGO (10-15), BOTZ (10-16)
- Left Trail danger zone: TLT (10-12, 5.16%, 10-16 7.61%)
Weekly Discussion Review
| Date | Ticker | Verdict | Headline | Subsequent weekly move | Review |
|---|---|---|---|---|---|
| 10-13 | XLV | REDUCE (0.5, MEDIUM) | Defensive rotation and the trend above the MA150 remain valid, but rate and CPI events loom and there is no health care-specific catalyst. Enter at only 50% of normal size. (Trail 17.76%) | +2.74% | Partially correct. The direction was right, and the half size captured half of the gain |
| 10-14 | XLV | REDUCE (0.5, MEDIUM) | The medium-term trend above the MA150 and the trail buffer remain valid, but a rate event and a thin MA50 cushion argue for caution. Enter at only 50% of normal size. (Trail 16.44%) | +4.16% | Partially correct. The MA50 cushion the Bear flagged held, and post-CPI defensive demand produced the week's largest gain |
| 10-14 | MU | REDUCE (0.5, HIGH) | Earnings visibility remains valid, but rate and oil risk-off and a thin trail argue for caution. Enter at only 50% of normal size. (Trail 5.96%) | -7.80% | Missed. Even at half size the loss was large and the Trail buffer shrank to 0.05%. SKIP was the right call |
| 10-15 | XLV | REDUCE (0.5, MEDIUM) | The trend above the MA150 and the trail buffer remain valid, but a rate event and thin MA alignment argue for caution. Enter at only 50% of normal size. (Trail 18.88%) | +1.58% | Partially correct. The uptrend continued, and as the Bear worried about entering right after a surge, the gain was small |
| 10-15 | MU | SKIP (0.0, HIGH) | Trail of 2.85% is below the stop threshold. This signal is not executed. (Trail 2.85%) | -3.86% | Correct. The automatic override avoided further losses |
| 10-16 | MU | REDUCE (0.5, MEDIUM) | The medium-term trend above the MA150 and export fundamentals remain valid, but a trail of 4.23% barely clears the threshold ahead of the FOMC. Enter at only 50% of normal size. (Trail 4.23%) | -5.63% | Missed. The next day's -5.63% in one session cut the Trail buffer to 0.05%. Barely clearing the threshold was not grounds for entry |
| 10-17·10-18 | MU | SKIP (0.0, HIGH, 10-18 reuses the prior discussion) | Trail buffer of 0.05% falls far short of the 4% threshold. This signal is not executed. (Trail 0.05%) | No weekend trading | Cannot assess. To be confirmed after the 10-19 Asian open |
Weekly Strategy Overview
Entry signals for core indexes and mega-caps held, but their Trail buffers shrank sharply in a week. QQQ went from 27.80% to 23.04%, XLK from 26.61% to 20.27% and NVDA from 22.99% to 17.99%. Apart from GOOG, new entries came from outside AI, such as CPER and LLY, while exits and stop-line breaches clustered in the AI value chain: AIPO, BOTZ, AVGO, SMH and MU. The lesson from eight discussions is the same as in W41. For candidates with a Trail buffer below 7%, holding off was better than half size. Both of MU's REDUCE calls ended in losses, and only the REDUCE on XLV, with its wide Trail buffer, made money.
7. Weekly Sentiment Flow
| Date | Reddit verdict | Key topics |
|---|---|---|
| 10-12 (Mon) | — | Report not generated |
| 10-13 (Tue) | Neutral | Broadcom CEO's "AI investors are gamblers" remark, worsening market breadth with "only the Mag 7 and energy are rising," Brent at $106 |
| 10-14 (Wed) | Bearish | $800 billion of Asian market cap wiped out, unwinding of the semiconductor crowding, WSB speculation on buying the MU dip |
| 10-15 (Thu) | Bearish | CoreWeave bonds and CDS, neocloud collapse, September CPI, loss screenshots |
| 10-16 (Fri) | Bearish | PPI 6.3% shock, "49% of the S&P 500 is AI-related," KOSPI -7.57%, cynicism about the rebound |
| 10-17 (Sat) | Bearish | AI debt concerns and data center bond dump, oil breaking $100, views split between holding cash and buying the dip |
| 10-18 (Sun) | Bearish | Semiconductors down nine days in a row, IMF AI bubble warning, fears of liquidation in 4x leveraged semiconductor ETFs |
8. Daily Summaries
| Date | Day | One-line summary | Link |
|---|---|---|---|
| 10-12 | Mon | Report not generated | — |
| 10-13 | Tue | SMH -2.05% on the CXMT memory announcement, S&P 500 7,807.24 (-0.06%). KOSPI 6,384.24 (-3.65%), net foreign selling of KRW 2.0186 trillion | Daily report |
| 10-14 | Wed | Mixed bank earnings left the S&P 500 flat at -0.02%. KOSPI 6,035.35 (-5.46%), VKOSPI spiked to 48.53 | Daily report |
| 10-15 | Thu | Nasdaq -1.88% and SMH -3.98% on the September CPI beat at 3.7% and CoreWeave shares -15%. XLV +2.53%, XLP +2.22% | Daily report |
| 10-16 | Fri | Dow +1.08% as the 10-year fell to 5.09% despite PPI at 6.3%. KOSPI 5,554.22 (-7.57%) with a circuit breaker | Daily report |
| 10-17 | Sat | Nasdaq -2.15% for its worst week since June. VIX 19.99, WTI $101.41. KOSPI +2.05%, its first rebound in eight sessions | Daily report |
| 10-18 | Sun | Weekly wrap: S&P 500 -1.95%, Nasdaq -4.48%, KOSPI -14.46%. Eight straight down days in semiconductors is the longest since 2008 | Daily report |
9. Next Week's Outlook
Key Scheduled Events
- 10-19 (Mon): Asian open. Watch whether the KOSPI and Nikkei price in the 10-16 US session's EWY -3.70% and SMH -3.41%
- 10-23 (Fri): Bank of Korea Monetary Policy Board meeting (per press reports). A hold at the 3.00% policy rate is the prevailing forecast, and many see a hike in November
- During W43: Big tech Q3 earnings season gets into full swing. Meta's capex guidance is seen as the first test of whether AI credit concerns spread (schedule per press reports)
- 10-27 (Tue): SK hynix Q3 earnings. Samsung Electronics' board is expected to approve a cash dividend of about KRW 30 trillion in late October
- 10-27~28: FOMC (decision 10-28 at 14:00 ET, no economic projections). A hold in October is favored, with about a 74% probability of a December hike
- Later: BOJ decision 10-30, US midterm elections 11-03, Anthropic IPO marketing may begin the week of 11-09, US-China reciprocal tariff truce expires 11-10
Key Things to Watch
- Whether a second shock hits Asian semiconductors: The KOSPI at 5,668.05 is about 4% from the weekly low of 5,450.81. If net foreign buying (KRW 341.4 billion on 10-16) continues, the decline gets framed as a flow shock; if a Monday gap-down coincides with leveraged liquidations, the low gets retested.
- How far AI credit concerns spread: What has been confirmed so far is credit deterioration at debt-reliant neoclouds like CoreWeave. If HYG holds around 76.86 (-0.48%) and hyperscaler capex guidance is maintained, an oversold bounce in semiconductors follows. If HYG slides further, credit problems spread to large-cap funding.
- The divergence between inflation and rates: CPI is 3.7% and PPI 6.3%, yet the 10-year fell to 5.10%. If safe-haven demand was the cause, yields will rise back when stocks rebound. Whether the 10-year breaks above 5.2% again before the FOMC will set the ceiling on a growth-stock rebound.
- Staying power of defensive rotation: XLP, XLE and XLV are up +3.5~5.0%, so relative strength is already large. Once a semiconductor rebound starts, this gap could unwind quickly, so watch SMH's performance relative to XLE.
Risk Factors
- AI credit crunch spreading to high yield: If distress in B-rated AI infrastructure bonds spreads across high yield, HYG falls more than 1% and the VIX tops 25. Hopes for data center investment fade, and the semiconductor decline transmits to mega-caps.
- Oil settling at $110: If Brent settles above its weekly high of $110.00, October CPI could exceed 3.7%. The probability of a December hike rises further and the 10-year moves back above 5.3%.
- Second plunge in Korea: The cause of foreign selling has not been resolved, and only a rebound has occurred. If net institutional selling continues and EWY weakness is priced in, the 5,450 level breaks and the won's strengthening trend (KRW 1,329.60) could also reverse.
- Hawkish FOMC signal: Even if a hold in October is favored, a hint of further hikes late in the year would increase valuation pressure on tech stocks. The statement and press conference are the points of confirmation.
- Tariff expiry and midterm elections: Replacement tariff news is likely to cluster around the 11-10 truce expiry, and the 11-03 midterms add political volatility. Volatility in semiconductors and exporters would rise.
This Week's Q&A
- This week, as stocks fell, long-dated US Treasuries rose and made up a good part of the losses. With inflation in the high 3% range, will bonds keep acting as a shield next week?
- This week the KOSPI fell more than 14%, but UK stocks actually rose 3%. Can spreading money across several countries avoid a shock like this?
- This week the semiconductor ETF was pushed to its stop line, and new buy signals turned on for health care, Eli Lilly and copper. Can I switch according to the signals, and was the midweek call to 'buy only half' correct?