AI is leading to plenty of investment opportunities, and in some unexpected places too.

Toto Ltd. — Japan’s century-old maker of heated toilet seats and Washlet bidets — has seen its stock more than double over the past year, and the reason has nothing to do with bathroom fixtures. The company turns out to be a critical supplier to the global semiconductor industry, and as AI spending has driven a surge in demand for memory chips, Toto has quietly emerged as one of the biggest beneficiaries of the boom.

The Ceramics Business Nobody Knew About

Toto has been making electrostatic chucks — precision ceramic discs used inside chip fabrication equipment — since 1988. An electrostatic chuck holds a silicon wafer perfectly flat during manufacturing processes, using voltage applied across embedded electrodes to pin the wafer without mechanical contact. They have to be extraordinarily pure and temperature-stable; even microscopic contamination or a slight warp ruins the wafer.

For roughly three decades, this side of the business barely broke even. Toto’s ceramics expertise had found a niche in semiconductor manufacturing, but volumes were modest and the segment attracted little investor attention. The company was known, globally, for its toilets.

What changed was the AI infrastructure buildout. As hyperscalers poured capital into data centers, demand for NAND flash memory — the storage technology inside AI servers — accelerated sharply. NAND manufacturers like Samsung, SK Hynix, Micron, and Kioxia raced to expand production capacity. And all of that expansion required more of the specialized equipment used to manufacture chips, which in turn required more of the components inside that equipment — including Toto’s electrostatic chucks.

Toto’s chucks are used specifically in Lam Research’s cryogenic etching tools, which carve the deep, narrow holes needed to build 3D NAND memory. Building modern 3D NAND requires stacking hundreds of memory cell layers vertically — architectures today exceed 200 layers, and roadmaps project reaching 1,000 layers by 2030. Each additional layer means more etching, more tool usage, and more replacement demand for consumable chucks. Toto and Lam Research have a relationship going back to 1990, and Lam awarded Toto its Supplier Excellence Award in both 2023 and 2024.

The Numbers That Got Investors’ Attention

For the fiscal year ended March 2026, Toto’s advanced ceramics division generated ¥28.9 billion (around $182 million) in operating profit — more than its core housing-equipment business, and accounting for over half of the company’s record ¥53.8 billion in group-wide operating profit. The ceramics segment now carries an operating margin of approximately 43%, compared to around 4% for the bathroom fixtures side. Profit attributable to shareholders surged 230% year-on-year.

Those numbers are striking when you consider that the ceramics division accounts for a small fraction of Toto’s total revenue. The housing equipment business — the toilets, sinks, and fittings — makes up about 91% of revenues. The ceramics segment is generating the lion’s share of the profits on a fraction of the sales, which is what a 43% margin does.

The stock surged 18% in a single session in May when these earnings were disclosed, then jumped another 11% in early June when CTO Ryosuke Hayashi confirmed that chip-related capital expenditure would soon exceed spending on housing equipment. Toto is putting approximately ¥30 billion toward semiconductor-related capex and research through fiscal year 2028, and a new kiln building at its Buzen plant is scheduled to come online in January 2027, adding over 20% to current production capacity.

The Activist Investor Who Spotted It First

The market didn’t figure this out entirely on its own. In February 2026, UK-based activist fund Palliser Capital — which had quietly become a top-20 shareholder — sent a letter to Toto’s board calling the company “the most undervalued and overlooked AI memory beneficiary.” Palliser argued that Toto had a five-year competitive lead over rivals in ceramics technology, that the market was severely mispricing the stock because of poor disclosure around the segment, and that fixing that gap could unlock more than 55% upside. Goldman Sachs upgraded the stock to Buy around the same time.

Palliser’s core argument was structural: Toto’s ceramics business benefits from growing demand regardless of where memory prices are in the cycle. As 3D NAND architectures keep adding layers, the volume of cryogenic etching required multiplies — and so does replacement demand for Toto’s chucks. It’s not a bet on memory prices staying high; it’s a bet on chips continuing to get more complex.

The chemistry that connects Toto’s plumbing heritage to its semiconductor business is alumina — aluminum oxide — the dominant material in both high-end ceramic sanitary ware and precision electrostatic chucks. Decades of working with alumina at extremely high purities gave Toto the materials science foundation to develop chucks that could meet the exacting demands of modern fabs. Toto is now the second-largest electrostatic chuck producer globally.

A Broader Pattern

Toto is an extreme example of something that’s been playing out across the AI supply chain: the AI boom has a way of finding unexpected beneficiaries far removed from the obvious Nvidia-and-hyperscaler story. Memory chipmakers like SK Hynix and Micron have crossed trillion-dollar valuations on the back of AI-driven demand. Now a Japanese toilet company is being re-rated as a semiconductor materials company.

The Toto story also illustrates how activist investors are increasingly combing through traditional industrial companies for hidden exposure to the AI buildout — businesses where legacy branding masks a materials science or engineering capability that happens to be exactly what the chip industry needs. The market tends to price these companies by their most visible product. Sometimes the most valuable thing they make is something most investors have never heard of.

For Toto, that thing has been sitting in semiconductor fabs since 1988.