Based on US stock returns through the Oct 6, 2026 close. Weekly breadth counts all US stocks; "liquid names" are stocks over $5 with market cap over $100M, average volume over 1M shares and an average daily range (ATR) over 2.4%. Inferences are labelled (inference).
Market backdrop
| ETF | 1M | 3M | 6M |
|---|---|---|---|
| SPY | +1.7% | +4.2% | +18.2% |
| QQQ | +5.7% | +7.1% | +29.1% |
| IWM | -4.5% | -5.0% | +11.2% |
| SMH | +10.2% | +8.8% | +58.2% |
| IGV | +8.3% | +18.1% | +38.1% |
| XLE | -1.6% | +16.7% | +6.0% |
Leadership is narrow: semis (SMH) and software (IGV) are well ahead of SPY. Small caps (IWM 1M -4.5%) and financials (XLF 1M -5.7%) are lagging.
Weak groups (liquid-name averages):
- Agricultural Inputs: 1W -11.7%, 1M -23.9%
- REIT-Mortgage: 1M -18.7%, 3M -21.8%
- Casinos: 1M -15.0%, 3M -23.7%
- Precious metals: Other Precious Metals 1M -14.7%, Gold 1M -11.6% (GDX 1M -10.4%)
- Packaged Foods: 1M -10.3%
- Biotechnology (111 liquid names): 1W -5.8%, 1M -10.2% (XBI 1M -6.8%)
- Sector ETFs: URA 1M -12.0%, TAN 1M -9.6% (3M -19.0%), ITA 1M -6.8% (3M -15.0%), XLU 1M -5.3%
Weekly themes
1. AI optical / networking (Communication Equipment + optical semis)
Breadth:
- Communication Equipment: 12/54 (22%) up >=10% in 1W, and 7 of the 16 liquid names are among them. Liquid-name average 1W +8.5%, 1M +9.1%.
- Semiconductors: 16/101 (16%) up >=10% in 1W.
- This was the #2 industry by weekly share.
| Ticker | 1W | 1M | 3M |
|---|---|---|---|
| AAOI | +29.3% | +16.7% | +13.8% |
| CIEN | +25.0% | +30.0% | +5.9% |
| MTSI | +23.4% | +27.6% | +15.0% |
| MXL | +17.9% | +64.4% | +27.4% |
| LITE | +16.4% | +15.8% | +62.2% |
| COHR | +15.8% | +12.1% | +7.7% |
| VIAV | +15.1% | +24.2% | +19.7% |
| CRDO | +14.8% | +31.6% | -10.4% |
| HPE | +14.6% | +25.9% | +62.3% |
Why:
- Oct 1: Bernstein initiated Ciena at Outperform with a $440 target, calling optical transport an AI bottleneck. It noted near-term supply limits (ceramic packaging, pump lasers, memory) easing after 2027 (BingX).
- Oct 6: CIEN rose as much as 14% intraday (closed +11%) after a peer gave a 60–70% optical-interconnect growth outlook (Yahoo, TradingKey).
- MaxLinear gained +50.7% in September on its optical DSPs for AI data centers (Motley Fool).
- The theme's base is Lumentum's August blowout quarter: revenue +109% YoY, guided $1.225–1.275B (247wallst).
2. Power / analog semis
Breadth: These names are inside the Semiconductors weekly 16%. ON, VSH, WOLF and STM are each up >=+10% in 1W.
| Ticker | 1W | 1M | 3M |
|---|---|---|---|
| VSH | +16.6% | +20.2% | -10.3% |
| ON | +13.6% | +21.4% | -5.3% |
| WOLF | +13.2% | +10.2% | -11.6% |
| STM | +10.3% | +13.0% | -12.7% |
| TSEM | +10.2% | +17.6% | +21.9% |
Why: No single catalyst found for this week.
- Background driver: NVIDIA Vera Rubin and 800V DC power. onsemi's CEO cited power content per rack rising from about $15k toward $115k. A Mizuho note on Aug 16 said the Rubin ramp was faster than expected (Yahoo, Aug 17).
- 3M returns are still negative while 1M is +10–21%. (inference) This looks like a re-acceleration off a base, not an extended trend.
3. Refiners
Breadth: Oil & Gas Refining & Marketing ranked #1 by weekly share:
- 5/19 (26%) up >=10% in 1W, including 4 of the 10 liquid names.
- Liquid-name average 1W +7.9%.
| Ticker | 1W | 1M | 3M |
|---|---|---|---|
| CVI | +13.5% | +24.5% | +100.4% |
| MPC | +10.3% | +8.7% | +62.3% |
| PBF | +10.2% | +8.0% | +71.0% |
| DK | +10.1% | +0.0% | +44.6% |
| DINO | +8.5% | +5.8% | +55.0% |
| VLO | +8.1% | +9.5% | +57.5% |
Why:
- Crack spreads widened sharply on Strait of Hormuz disruption, with the 3-2-1 near $69/bbl per news reports (cnhinews).
- MPC's Q2 2026 R&M margin was $36.33/bbl vs $17.58 a year earlier (MPC 10-Q).
- No single new catalyst was found for this specific week.
4. Engineering / design software (M&A re-rating)
Breadth:
- Software-Application: 23/233 (10%) up >=10% in 1W.
- Software-Infrastructure: 19/145 (13%) up >=10% in 1W.
| Ticker | 1W | 1M | 3M |
|---|---|---|---|
| PTC | +40.3% | +44.8% | +54.4% |
| SNPS | +21.7% | +28.9% | +15.7% |
| BSY | +15.6% | +9.5% | +10.9% |
| GWRE | +15.4% | +9.9% | +20.0% |
| ADSK | +13.8% | +9.0% | +8.9% |
| CDNS | +10.9% | +26.6% | -3.1% |
Why:
- Schneider Electric agreed to buy PTC for $205/share in cash ($22.6B, a 42.3% premium).
- Autodesk rallied on the read-through that strategic buyers will pay up for industrial AI and engineering software (Benzinga, Yahoo, Tradingpedia).
- Synopsys investor day: SNPS announced GPT-Synopsys with OpenAI and a multi-year custom silicon IP deal with AWS, and analysts raised targets (247wallst).
- Flag: PTC is a takeover, so it is now pinned near the deal price, and SNPS was a single-company event. (inference) The sympathy moves in ADSK, BSY and GWRE are a valuation re-rate, not an earnings-driven theme.
5. Cybersecurity (persistent, cooling)
Breadth: These names are inside the Software-Infrastructure weekly 13%. Monthly is stronger than weekly.
| Ticker | 1W | 1M | 3M |
|---|---|---|---|
| TENB | +12.8% | +17.1% | -2.8% |
| S | +10.7% | +32.8% | +42.1% |
| RBRK | +9.6% | +37.3% | +44.5% |
| ZS | +7.0% | +31.1% | +42.0% |
| OKTA | +6.7% | +30.5% | +47.3% |
| CRWD | +6.1% | +32.8% | +43.3% |
Why:
- Sept 14: The sector's best day in years after AI-safety warnings from frontier-lab CEOs, including Anthropic's Dario Amodei, about autonomous cyberattacks. CRWD and ZS gained about +12%, and PANW +11% (247wallst).
- No new catalyst was found this week. 1W gains (+6–13%) are much smaller than 1M (+17–37%).
6. Grid / electrical E&C
Breadth: Engineering & Construction: 8/51 (16%) up >=10% in 1W, but 0/51 are up >=25% in 1M. Liquid-name average 1M is -1.1%.
| Ticker | 1W | 1M | 3M |
|---|---|---|---|
| PRIM | +14.4% | +12.6% | -2.3% |
| MYRG | +12.6% | +12.6% | -22.6% |
| STRL | +11.6% | +12.2% | -16.4% |
| PWR | +10.4% | +12.6% | +9.6% |
Why: No single catalyst found. (inference) This is a bounce in names that are still down over 3M, not a durable theme yet.
Event-driven (one-offs, not themes)
Brazil election. In the Oct 4 first round, Flávio Bolsonaro took 47.03% vs Lula's 45.16%, with a runoff on Oct 25. The Ibovespa hit a record near 210,000, up almost +9% intraday on Oct 5 (CNBC, France24, Americas Quarterly).
1W moves in Brazilian ADRs:
- XP +46.7% (no XP-specific catalyst found)
- INTR +37.0%, BBD +34.2%, NU +26.8%, ITUB +25.5%
- STNE +25.2%, PAGS +21.8%
- SBS +23.7%, SID +20.6%, PBR +15.3%, CIG +15.1%, GGB +10.3%
(inference) Brazil names (SID, GGB) explain part of Steel's weekly breadth (4/22, 18%). US steel was milder: CLF +11.3%, NUE +6.3%, STLD +7.3%. CLF had a month-long rebound with no company news per 247wallst.
Monthly themes
Monthly ranking by liquid-name share up >=25% in 1M, >=50% in 3M and >=50% in 6M:
| Industry | Liquid names | 1M>=25% | 3M>=50% | 6M>=50% | avg 3M | avg 6M |
|---|---|---|---|---|---|---|
| Oil & Gas Refining | 10 | 0% | 60% | 80% | +47.4% | +59.1% |
| Healthcare Info Services | 13 | 8% | 23% | 69% | +23.3% | +80.0% |
| Diagnostics & Research | 15 | 20% | 13% | 60% | +33.5% | +88.7% |
| Computer Hardware | 17 | 12% | 24% | 59% | +26.7% | +87.3% |
| Semiconductors | 44 | 16% | 2% | 39% | +6.1% | +70.7% |
| Communication Equipment | 16 | 25% | 13% | 19% | -4.1% | +16.9% |
Advertising Agencies ranks high, but its average is driven by TJGC, a $0.2B micro-cap at 3M +518%, so it is excluded as noise.
1. Refiners (most durable)
See weekly theme #3 above.
- 6 of 10 liquid names are up >=50% in 3M, and 8 of 10 are up >=50% in 6M.
- 6M returns: CVI +73.8%, PBF +79.5%, DINO +88.4%, MPC +76.2%, VLO +66.7%.
- Catalyst: elevated crack spreads from Hormuz disruption (sources above).
2. Genomics / AI-bio tools (resting leaders)
| Ticker | 1M | 3M | 6M | 1W |
|---|---|---|---|---|
| TXG | +23.0% | +113.2% | +269.7% | -10.4% |
| CDNA | +26.8% | +125.3% | +261.0% | -0.4% |
| TWST | +30.4% | +83.4% | +233.1% | -10.3% |
| SDGR | +44.3% | +75.3% | +153.7% | -4.7% |
| ILMN | +29.6% | +42.6% | +116.3% | +0.6% |
| NTRA | +23.6% | +42.4% | +91.5% | -3.3% |
| TEM | +12.0% | +19.8% | +53.7% | -12.8% |
Why:
- The earlier issue cited a TXG product launch and a TWST–Lilly deal plus target raises. Those were not re-verified in this run.
- No single catalyst found for the 1W pullback. It coincides with broad biotech weakness: Biotechnology liquid-name average 1W -5.8%, XBI 1M -6.8%.
- (inference) A strong monthly trend with a red week is the "leaders of a growing industry while consolidating" setup.
3. AI storage / servers
| Ticker | 1M | 3M | 6M | 1W |
|---|---|---|---|---|
| QMCO | +36.8% | +230.4% | +448.7% | +1.9% |
| P (Everpure) | +45.6% | +88.2% | +137.9% | +13.2% |
| SMCI | +7.9% | +65.6% | +91.7% | +5.9% |
| NTAP | +20.8% | +37.8% | +134.0% | +9.2% |
| DELL | +7.5% | +37.5% | +222.9% | +6.4% |
| HPE | +25.9% | +62.3% | +186.5% | +14.6% |
Why:
- Everpure (formerly Pure Storage) was September's top S&P 500 gainer, up >40%.
- At its Financial Analyst Meeting it guided FY28 revenue to $7.0–7.3B (growth up to 45%), driven by AI and hyperscale demand (Stocktwits, Finviz).
- STX diverges: 1W -11.8%, 1M -10.9%. No catalyst found.
4. AI compute / connectivity semis
| Ticker | 1M | 3M | 6M | 1W |
|---|---|---|---|---|
| MXL | +64.4% | +27.4% | +493.7% | +17.9% |
| ALAB | +34.9% | +1.8% | +227.6% | +8.9% |
| AMD | +28.4% | +25.8% | +193.2% | +6.9% |
| MRVL | +27.3% | +24.4% | +162.4% | +9.0% |
| RMBS | +31.3% | +7.7% | +24.2% | +10.6% |
| FORM | +28.6% | +33.2% | +34.4% | +3.7% |
Why:
- This overlaps with the optical theme (MXL DSPs; source above). No other single catalyst was found for this group.
- (inference) Semis average 6M is +70.7% but 3M is only +6.1%, so they rested through summer and are re-accelerating in 1M (+13.5% average, SMH 1M +10.2%).
5. Cybersecurity
See weekly theme #5 above. 1M returns are +30–37% on CRWD, ZS, OKTA, S and RBRK, driven by the Sept 14 AI-safety bid.
Weekly vs monthly
| Theme | Weekly | Monthly | Read |
|---|---|---|---|
| AI optical / networking | Hot (CommEq 22% at >=10% 1W) | 1M strong (25% of liquid names at >=25%), 3M mixed | Starting / re-accelerating |
| Power / analog semis | Hot (ON/VSH/WOLF/STM +10–17%) | 1M +10–21%, 3M negative | Early. Not durable yet |
| Refiners | Hot (#1 weekly share) | #1 durable (80% at >=50% 6M) | Extended trend. Strength confirmed |
| Engineering software | Hot (PTC +40%) | Weak except PTC/SNPS | M&A one-off plus re-rate |
| Cybersecurity | Moderate (+6–13%) | Strong (1M +30–37%) | Durable, cooling after the Sept spike |
| Genomics / AI-bio | Red (TXG/TWST about -10%) | Strong (3M +75–125%) | Durable theme pulling back = resting leaders |
| AI storage / servers | Mixed (P +13%, STX -12%) | Strong (6M +134–449%) | Durable; leader P still pushing |
| Grid E&C | Hot (16% at >=10% 1W) | 0% at >=25% 1M, 3M negative | Bounce only |
| Brazil ADRs | Very hot (+15–47%) | n/a | Election one-off; runoff Oct 25 |
What changed since last week
Caveat: this is the first issue. There is no earlier snapshot, so a true week-over-week breadth comparison is not possible. The only prior notes (2026-10-07) cover this same week, so this comparison is against those notes.
NEW in this issue (not in prior notes):
- Engineering/design software M&A re-rate: Schneider–PTC $22.6B, with ADSK, BSY and GWRE in sympathy.
- Brazil basket widened beyond STNE/PAGS to banks and brokers (XP +46.7%, INTR +37.0%, BBD +34.2%, ITUB +25.5%) and to steel and utilities (SID, GGB, SBS, CIG).
- Steel weekly breadth (18%), partly Brazil-driven.
PERSISTENT:
- AI optical/networking
- Refiners
- Cybersecurity, cooling on 1W
- Genomics/AI-bio tools, pulling back
- AI storage/servers
- Power/analog semis
- Grid E&C (weekly only)
- Tankers (HAFN 3M +41.1%, NAT 3M +39.6%) stay positive but did not rank this week.
DROPPED / COOLING:
- Gold/precious metals: Gold liquid-name 1M -11.6%, GDX 1M -10.4%
- Uranium: URA 1M -12.0%
- Solar: TAN 3M -19.0%
- Defense: ITA 3M -15.0%
- Biotech broadly: 1W -5.8%, 1M -10.2%
- Agricultural Inputs: 1M -23.9%
Sources
- BingX – Ciena Bernstein $440 Outperform, Oct 1
- Yahoo – Ciena 60-70% optical growth outlook
- TradingKey – CIEN +11% Oct 6
- Motley Fool – MaxLinear +50.7% in September
- 247wallst – Lumentum blowout earnings, Aug 12
- Yahoo – Power semis on Vera Rubin ramp, Aug 17
- cnhinews – refiners / crack spreads
- SEC – Marathon Petroleum Q2 2026 10-Q
- Benzinga – PTC +35% premarket
- Yahoo – $22.6B reason Autodesk is up
- Tradingpedia – Autodesk jumps as PTC deal reframes valuation
- 247wallst – Synopsys investor day
- 247wallst – Cybersecurity surge on AI-safety warnings, Sept 14
- Stocktwits – Everpure September S&P winner
- Finviz – Everpure AI-fueled surge
- CNBC – Brazilian stocks jump on Bolsonaro lead
- France24 – Brazilian stocks surge to record
- Americas Quarterly – Bolsonaro and Lula advance to runoff
- 247wallst – Cleveland-Cliffs month-long rebound, Sept 22