Japan Stock of the Day | Kabutaro & Friends

On September 1, 2026, the most talked-about Japanese stock online was Sumitomo Chemical <4005>.
Background: On August 31 the company announced it had established four-inch mass production of InP epitaxial wafers at its Ibaraki Works in Hitachi City, Ibaraki Prefecture, and begun sales. The wafers are a core material for the optoelectronic fusion technology behind AI data centers. Drawing on composition control technology cultivated over more than 25 years in gallium arsenide and gallium nitride, the company aims for sales of about 10 billion yen from this product group by the middle of the 2030s. On September 1 it further announced that it had developed, with Gutenberg, a liquid crystal polymer (LCP) filament and forming technology for 3D printers. It combines light weight with high thermal conductivity and strength comparable to aluminum alloy, with expected uses in semiconductor production components, humanoid-related parts and eVTOL aircraft, and samples will be offered within this year. The stock closed at 620.1 yen, up 47.9 yen (+8.37%), the top gainer on the Tokyo Stock Exchange Prime Market.