Nabtesco (TSE: 6268, OTC: NCTKF) makes the RV reducer, the cycloidal gearbox inside the big joints of most industrial robots from Fanuc, Yaskawa, ABB and KUKA. By its own estimate it holds about 60% of that market. Humanoid robots are a newer and less natural fit, because their lighter joints mostly use strain-wave gears or roller screws, but Nabtesco is moving into small reducers and humanoid actuators. Meanwhile its core business is having a strong 2026. This page is part of our Tesla Optimus stocks hub.
- Ticker: 6268, Tokyo Prime; NCTKF over the counter in the US.
- H1 2026: sales JPY 167.4B (+16.8%), operating profit JPY 15.8B (+72.4%), orders +33%.
- Guidance: FY2026 sales JPY 344B, operating profit JPY 32.6B; buyback up to JPY 15B.
- Price: about JPY 4,293 (Oct 20, 2026), market value near JPY 500B.
- Humanoids: RV mini deliveries from H2 2026 and German-made strain-wave gears; no Tesla link reported.
Nabtesco at a Glance
| Item | Detail |
|---|---|
| Listing | 6268 · Tokyo Stock Exchange Prime |
| US quote | NCTKF (OTC) |
| Fiscal year | January to December |
| Recent price | JPY 4,293 (Oct 20, 2026); 52-week range JPY 3,196-6,113 |
| Market value | About JPY 499B; trailing P/E about 27 |
| Dividend | JPY 82 per share planned for 2026 |
| Segments | Component Solutions (precision reducers), Transport Solutions (rail, aircraft, marine), Accessibility Solutions (automatic and platform doors) |
Price data from Yahoo Finance. The stock fell about 8% in one mid-October session as Japanese robot names sold off, per ad-hoc-news. Check a live quote before trading.
What an RV Reducer Is, and Why It Matters
An RV reducer combines a first planetary stage with a second cycloidal stage. It handles high torque and shock loads with very low backlash and long life, which makes it the standard choice for the base, shoulder and elbow of a six-axis industrial robot that lifts tens or hundreds of kilograms. Strain-wave gears, the specialty of Harmonic Drive Systems, are lighter and thinner and dominate wrists and small robots. A humanoid needs compact, light joints, so most humanoid designs lean toward strain-wave or planetary gears, with roller screws for linear motion. See our Optimus actuator guide for the joint-by-joint picture.
Reducers are only part of Nabtesco. Component Solutions was about 27% of first-quarter 2026 sales; automatic doors (including train platform doors), rail and aircraft equipment, and marine controls make up the rest.
First-Half 2026 Results
| Metric (JPY) | H1 2026 | Change YoY |
|---|---|---|
| Group sales | 167.4B | +16.8% |
| Group operating profit | 15.8B (9.5% margin) | +72.4% |
| Group orders | 198.5B | +33.1% |
| Component Solutions sales | 45.5B | +23.6% |
| Component Solutions orders | 48.0B | +26.0% |
| Component Solutions operating profit | 4.8B | +160.8% |
Group figures from Quartr's summary of the July 31 report; segment figures from the original release referenced in Nabtesco's August 14 correction notice. Precision reducer sales rose on robot demand from automakers in China and South Korea and on general industrial demand. Nabtesco raised 2026 guidance to JPY 344.0 billion of sales and JPY 32.6 billion of operating profit, lifted the dividend to JPY 82 and announced a buyback of up to JPY 15 billion. Third-quarter results were scheduled for October 30, 2026; we had not verified those figures at publication.
The September Restatement
During the interim review, Nabtesco's auditor found that the company had not fully recorded its share of retained earnings at TMT Machinery, a 33%-owned equity-method affiliate. The unrecorded amount was about JPY 2.6 billion. Rather than book it in one year, Nabtesco restated fiscal 2021 to 2025 and filed corrected reports on September 30, 2026. The adjustment sits below operating profit and increases profit and equity, so it is not a Nidec-style crisis, but it is a control lapse worth noting. Our Nidec page shows what a severe version looks like.
Nabtesco's Humanoid Moves
Nabtesco is approaching humanoids from two directions:
- RV mini: smaller RV reducers, with deliveries expected to start in the second half of 2026, according to an investor analysis on note.com citing company guidance. These target smaller robots and could fit heavier humanoid joints such as hips.
- Strain-wave gears and actuators from Germany: Nabtesco's European unit offers backlash-free strain-wave gears, short gears with what it says is 20% more torque and 40% longer life at the same size, hollow-shaft actuators and a digital gear with built-in position, torque and temperature sensing, made at an IATF-certified plant in Germany (Humanoid Robotics Technology).
Reality check: Nabtesco has not named a humanoid customer, and no Tesla relationship has been reported. In humanoids it is a challenger, while Chinese makers such as Leaderdrive already supply AgiBot and UBTech.
Nabtesco vs Harmonic Drive Systems
| Nabtesco (6268) | Harmonic Drive (6324) | |
|---|---|---|
| Core reducer | RV (cycloidal), large joints | Strain-wave, small and light joints |
| Humanoid fit today | Limited; new small products | Direct, but price pressure from China |
| Diversification | Doors, rail, aircraft, marine | Mostly robots, chip tools, medical |
| Valuation | ~27x trailing earnings | Far higher multiple |
Nabtesco is the steadier, cheaper industrial with a smaller humanoid option. HDS is the purer but pricier humanoid gear bet.
Risks
- Product fit: RV reducers are not the main humanoid gear type, so the humanoid upside depends on new products winning.
- China competition in reducers, where local makers compete on price.
- Cyclical robot demand tied to auto and electronics capex.
- Accounting controls: the TMT Machinery restatement was small but real.
- Currency: about half of sales are overseas, and foreign holders carry yen risk.
How to Buy Nabtesco Stock
- Tokyo: buy 6268 through a broker with Japan access, in 100-share lots.
- US OTC: NCTKF trades thinly; use limit orders.
- ETFs: humanoid and robotics funds such as KraneShares KOID have held Nabtesco; see our humanoid robot stocks guide.
This article is for information only and is not investment advice.
FAQ: Nabtesco Stock
What is Nabtesco's stock ticker?
Nabtesco trades on the Tokyo Stock Exchange Prime Market under the code 6268. In the US its shares are quoted over the counter as NCTKF.
What does Nabtesco make for robots?
Nabtesco is best known for RV precision reduction gears, a cycloidal reducer used in the heavy base, shoulder and elbow joints of industrial robots. By its own estimate it holds about 60% of the global market for precision reducers in medium-to-large industrial robots. It also makes strain-wave gears and actuators in Germany aimed at lighter joints, including humanoids.
Is Nabtesco a Tesla Optimus supplier?
No supply relationship with Tesla has been reported. Nabtesco's RV reducers are built for larger industrial robots, while Optimus joints are reported to use strain-wave reducers and roller screws sourced mainly from Chinese suppliers.
How did Nabtesco perform in the first half of 2026?
For January to June 2026, sales rose 16.8% to JPY 167.4 billion and operating profit rose 72.4% to JPY 15.8 billion. Orders grew 33.1%. Nabtesco raised its full-year forecast to JPY 344.0 billion of sales and JPY 32.6 billion of operating profit and announced a buyback of up to JPY 15 billion.
Why did Nabtesco restate its accounts?
In August 2026 Nabtesco said it had under-recorded its share of earnings from TMT Machinery, a 33%-owned equity-method affiliate, by about JPY 2.6 billion. It restated filings for fiscal 2021 through 2025 and submitted the corrected reports on September 30, 2026. The company said the effect raises profit and equity and does not change the earnings trend.
The Bottom Line
Nabtesco dominates the reducers in industrial robot arms, and 2026 is a strong year: first-half operating profit up 72%, orders up a third and a JPY 15 billion buyback. Its humanoid story is early, built on RV mini and German strain-wave gears, with no named humanoid customer and no Tesla link. At around 27 times earnings it is a reasonable way to own the robot-joint theme with less hype, but not a pure humanoid play.
Sources: Nabtesco correction notice (Aug 14, 2026), Quartr summary of Nabtesco H1 2026 results (Jul 31, 2026), Yahoo Finance (Oct 20, 2026), ad-hoc-news (Oct 15, 2026), GyokaiDigest on the Sep 30, 2026 restatement, note.com investor analysis (Jun 18, 2026), Humanoid Robotics Technology (Oct 2026). Not investment advice. Last fact-check: November 10, 2026.
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