The short version
- US trading held up overall. The 140 most-traded US stocks averaged $403B a day, about 0.97× their summer pace (1.01× September).
- AI hardware thinned out. AI Memory & Storage traded 0.78× its pace and AI Silicon 0.92×. Memory's share of the money fell from 15.4% to 12.4%.
- Defensive and real-economy sectors filled the gap. Medtech 1.35×, Aerospace 1.24×, Pharma & Biotech 1.21×, Telecom 1.20×, Staples 1.15×, Power & Grid 1.12×.
- Asia's AI trade cooled more. The top names traded 0.74× in Korea, 0.75× in Japan and 0.67× in China. The exceptions were Japan's chip testers and Korea's batteries.
How to read this
"Pace" compares a stock's (or sector's) average dollar volume per trading day in October with its average day from July to September. 1.00× means a normal day by summer standards. Above 1.1× is busy; below 0.9× is quiet. Sector figures add up the 140 most-traded US stocks, grouped by each company's main sector. Asian figures are converted to US dollars.
United States (the bulk of the money)
1. The overall level barely moved.
At $403B a day, US trading was a touch below its summer pace and slightly above September. October was a heavy month for price moves in AI stocks, but not for total trading. That distinction drives everything below.
2. Sectors: the money stayed in the market but changed seats.
| Sector | October $ | vs summer pace |
|---|---|---|
| Medtech & Health Services | $179B | 1.35× |
| Aerospace | $98B | 1.24× |
| Pharma & Biotech | $262B | 1.21× |
| Telecom (incl. SpaceX) | $446B | 1.20× |
| Consumer Staples | $197B | 1.15× |
| Power & Grid | $265B | 1.12× |
| Neoclouds | $210B | 1.11× |
| Media & Advertising | $711B | 1.08× |
| Banks & Brokers | $352B | 0.96× |
| AI Silicon | $1.39T | 0.92× |
| Devices (Apple) | $300B | 0.91× |
| Cloud & Software | $605B | 0.90× |
| Space & Defense | $144B | 0.85× |
| AI Memory & Storage | $1.10T | 0.78× |
The two biggest pools of money, AI Silicon and AI Memory, together traded nearly $2.5T in October. Both ran below their summer pace. The busiest sectors relative to normal were smaller ones, in healthcare, aerospace, staples and power. Semicap equipment was mixed: 0.97× for the month, but 1.16× in September, so its busy spell came before October.
3. The AI complex: still the biggest, just quieter.
- Micron ($574B) and NVIDIA ($500B) were still the two most-traded US stocks in October, but at 0.81× and 0.86× their pace.
- Sandisk traded $273B at 0.61×, the quietest of the large names.
- SK hynix's US line traded 0.80×, Applied Materials 0.80×, Palantir 0.79×, Microsoft 0.87× and Dell 0.88×.
- The exception inside AI was the neoclouds: the group ran 1.11× (1.26× in September), led by CoreWeave at 1.51×. Lumentum (optics) traded 1.25×.
On our own site, the company pages show that several of the month's largest price falls came on roughly normal volume. Intel, IREN and Nebius all traded within 0.94–0.97× of their pace. That is selling without a rush for the exit.
4. Where money crowded in.
- Medtronic: 3.45× its summer pace, the heaviest relative trading of any top-140 US name.
- Twilio 2.21×, Vistra 1.72×, Accenture 1.69×, Moderna 1.67×, Synopsys 1.64×, Constellation Energy 1.50×, Boeing 1.40×.
- Among the mega-caps, SpaceX ($349B, 1.23×), Meta ($331B, 1.19×) and Alphabet ($231B, 1.12×) traded above pace. Tesla ($308B) was right at 1.02×.
5. The US in one line.
October's AI selling was real in price, but light in volume. The extra activity went to healthcare, power, staples, aerospace and telecom.
South Korea
Korea's 17 largest names traded at 0.74× their summer pace.
- SK Hynix $77B, 0.66×, −19% on the month. Samsung Electronics $63B, 0.72×, −15%. The memory pair drove the slowdown.
- Batteries were the busy corner. Samsung SDI traded 1.68× (+7%) and LG Energy Solution 1.81× (+2%).
- Samsung E&A traded 2.05×, up 31%: the standout outside tech.
Japan
Japan's top 13 traded at 0.75× their pace.
- Kioxia was still Japan's most-traded name ($120B) but at just 0.42× its summer pace, down 26%.
- Chip testers bucked it. Advantest traded 2.05× ($80B, +2%) and Lasertec 1.62×.
- SoftBank Group fell 30% on 0.87× volume. Tokyo Electron (0.73×), Fujikura (0.72×) and Murata (0.81×) were all quiet.
China
China's top 14 traded at 0.67×, the coolest of the four markets (17 sessions, including Golden Week).
- The optics names that led China's AI rally cooled sharply. Zhongji InnoLight traded 0.62× (−31%) and Eoptolink 0.70× (−49%).
- CATL traded 1.22× and Kweichow Moutai 1.11× (+11.5%). China's money also leaned to batteries and staples.
October in five lines
- US trading volume held steady overall (0.97×). This was a rotation, not a retreat.
- AI memory's share of US money fell from 15.4% to 12.4%.
- Medtech, aerospace, pharma, telecom, staples and power all traded 1.1× pace or more.
- Asia's AI hardware names cooled to 0.67–0.75× pace; Kioxia was at 0.42×.
- The exceptions were Japan's chip testers (Advantest 2.05×) and Korea's batteries (LG Energy Solution 1.81×).
Source: InfinityVolume, Tiingo. Dollar volume from closing data, 1–30 Oct 2026. This is a description of trading activity, not investment advice.