Investment Thesis
Anchor participant in Japan's government-backed power semiconductor consolidation (Rohm + Toshiba TDSC + Mitsubishi Electric MoU signed March 27, 2026). FY2025 kitchen-sink SiC impairment of ¥158.4B clears the balance sheet — depreciation falls sharply from FY2026, driving OP ¥30B (+176%) guided recovery. Gen 5 SiC MOSFET (~30% lower on-resistance at Tj=175°C) in samples July 2026. Toyota bZ5 (HAIMOSIC JV, ~360K units/yr), Schaeffler (mass production Sep 2025), Infineon MOU (Sep 2025) all confirmed. CAUTION: Denso ¥1.3T bid withdrawn April 28, 2026; JV talks delayed — more complex than expected; P/B 2.56x vs 1.3x historical; analyst consensus PT ¥2,944 (-47% from market ¥5,400+).
Risk
1) JV EXECUTION RISK: Three-party JV delayed; Rohm president warned talks slower than expected (May 15, 2026). No equity structure/timeline yet. 2) VALUATION RISK: P/B 2.56x approaching historical peak; stock 3x'd from lows on JV/M&A speculation. Analyst consensus PT ¥2,944 vs ¥5,400+ = -47% implied downside. 3) SiC structural headwinds: Chinese vertical integration, BEV slowdown. 4) FY2025 NI -¥158.4B was WORSE than prior year ¥-57B — management credibility under scrutiny. 5) OP ¥30B guidance still formulating NI estimate — unusual complexity.
Monitoring Trigger
DO NOT ADD at current levels (P/B at historical peak, analyst consensus -47% below market). Re-entry conditions: (1) formal JV equity structure announced, OR (2) first clean profitable quarter in FY2026, OR (3) stock retraces to ¥3,500-4,000 range (closer to fundamental valuation). Q1 FY2026 results (Aug 2026) — watch OP run-rate toward ¥30B target.
Key Dates
Key Metrics
Business Segments
| Segment | Revenue | Share | Description |
|---|---|---|---|
| Discrete (SiC, MOSFET) | ¥210B | 44% | SiC power devices — core EV play |
| LSI / ICs | ¥175B | 37% | Analog, power management |
| Modules | ¥88B | 19% | Power modules, LED |
Supply Chain Evidence
| Evidence | Customer | Product | Detail |
|---|---|---|---|
| confirmed | Toyota bZ5 (China-market BEV) | SiC MOSFETs via HAIMOSIC JV (Rohm + Zhenghai Group), ~360K units/year | Mass production in HAIMOSIC JV (Shanghai). Toyota bZ5 targeted at China market. |
| confirmed | Schaeffler | SiC MOSFET bare chips for HV inverter brick targeting major Chinese carmaker | Mass production commenced September 2025. |
| confirmed | Infineon Technologies | SiC package second-source MOU — on-board chargers, PV, energy storage, AI data centers | MOU September 25, 2025. Mutual SiC package second-source for selected device lines. |
| confirmed (MoU stage) | Rohm + Toshiba TDSC + Mitsubishi Electric (JV MoU) | Combined power semiconductor operating company — #2 global position if JV completes | MoU signed March 27, 2026 by all 5 parties including JIP and TBJH. Combined share ~9.7-11% global, ranking above onsemi. Formal JV not yet established; talks delayed per May 2026 warning. |
Recent News
Primary IR Documentation
Values and insights cited from official company IR releases (earnings, 決算短信, MoUs, presentations).
Cites: Primary IR portal — FY2025 year-end materials posted May 12, 2026
https://www.rohm.com/ir
Cites: FY2025 full-year financial report (May 12, 2026)
https://fscdn.rohm.com/en/financial/financial-report/2603_financialresults_en.pdf
Cites: 4th-gen SiC MOSFET adopted in Toyota bZ5 (FAW Toyota); power module from HAIMOSIC JV — confirms Toyota EV SiC platform supplier thesis
https://micro.rohm.com/en/financial/ir-news-releases/250623_news_en.pdf