SUMCO Corporation
Cite as: Japan IR Index, SUMCO Corporation (3436), methodology GNT-BDS v1.1.1, reviewed 2026-10-01.
Findings and sources as of the review date shown. The company’s English disclosure may have changed since.
Where to start
Chosen from this company's lowest answers, easiest first. A quick fix uses material the company already has; a translation fix is usually met by translating a Japanese document (our note says whether this company has one). Questions that need a budget or a board decision are left out. Suggestions drawn from the research, separate from the scores.
F6 Multi-year financial data file (Excel or CSV) downloadable in English 0/5 Quick fix
Post the financial figures the company already publishes as an Excel or CSV file with English labels.
G6 Shareholder vote results disclosed in English 2/5 Quick fix
Publish the vote counts from the Japanese extraordinary report in English.
O5 Single page listing all English IR documents by date and type 3/5 Quick fix
Keep one English page that lists every IR document with its date and type.
O7 Named English IR contact published 3/5 Quick fix
Link a dedicated IR contact (form, address or e-mail) from the English IR section.
English disclosure assessment
All 34 questions reviewed by the editor against the public documents; this is not an independent audit. 4 answers corrected after re-checks (research errors) and 1 changed under a rule change between 21 Oct 2026 and 23 Oct 2026. These are changes to our record, not to the company’s disclosure. Changes to this record →
Compared with peers
| Peer group | Median | This company |
|---|---|---|
| Same sector (Metal Products) | 76.9 | 3 of 4 |
| Same size band (¥500bn–2tn) | 84.2 | 36 of 43 |
Compared with the companies covered here, not the whole market. Sector is the TSE 33-sector classification; market cap is from the TSE English-disclosure survey, Aug 2026; it only sets the size band, plays no part in the score, and is refreshed once a quarter. Ties share the higher rank.
Out of 100.
Of the 34 questions reviewed, 28 scored 3 or more and 4 found no qualifying English materials within the stated review scope. Read each score with its source and scope below.
Findings by question
F1Quarterly and full-year results summaries (tanshin) published in English5/5
Consolidated Financial Results for the six months ended 30 June 2026, in English, 6 August 2026. Checked against the Japanese tanshin for the same period: 12 English pages against 10 Japanese, so nothing was dropped in translation - neither version carries a segment note, SUMCO being a single-segment business. Source document →
F2English results summary is a full translation, not an excerpt5/5
Consolidated Financial Results for the Six Months Ended June 30, 2026 (English, 6 Aug 2026, 11 pages) checked against the Japanese 2026年12月期 第2四半期（中間期）決算短信 (9 pages). The sections match one for one: summary pages (results, dividends, the next-quarter forecast, notes on shares), qualitative information (business results and forecast explanation, with the FX assumption), balance sheet, income statement and comprehensive income, and the notes on going concern and on significant changes in shareholders' equity. The English is longer only because English text takes more room. SUMCO has a single segment, so neither version has a segment note. A whole translation, so 5. Source document →
F3Financial statements including notes available in English5/5
The latest period is fully covered in English. The Semiannual Securities Report for FY2026 (English, posted 28 Aug 2026, 25 pp) carries the semi-annual balance sheet, income statement, comprehensive income and cash flow statement, plus notes: balance sheet, income statement, cash flows, shareholders' equity, segment (single segment), business combinations and revenue recognition. The Annual Securities Report for FY2025 (141 pp) carries the full-year statements and notes. The quarterly tanshin carry the statements with short notes, as the Japanese ones do. Full statements and notes for the latest period, so 5. Source document →
F4Annual securities report available in English in any form4/5
The English Annual Securities Report for FY2025 (listed 31 Mar 2026, 141 pages) is complete in its parts: overview, business, risks, management analysis, facilities, shares, corporate governance, consolidated and non-consolidated financial statements. It ends at printed page 139 (guarantor information) without the independent auditor's report; its audit-certification paragraph is not that opinion. The English Securities Reports page lists no separate audit opinion (FY2025: the annual and semiannual reports only). Re-checked 21 Oct 2026 after the independent audit of 20 Oct; the earlier note said the auditor's report was included. Current and complete except the auditor's report, so 4. Source document →
F5Segment revenue and profit disclosed in English, consistent definitions4/5
Single-segment company, and it says so in English. The Annual Securities Report says 'the Group has only one segment' and the Semiannual Report says 'Segment information is not described since the Group has only one segment.' Product information is omitted because one product category exceeds 90% of sales. So the segment figures are the consolidated sales and operating profit, which the tanshin and the deck's quarterly trend page give every period. Beyond that, the only breakdown is sales by customer region (Japan, U.S., China, Taiwan, Korea, Europe), and only at the year end. Neither the tanshin nor the deck splits sales by wafer size (300 mm against 200 mm and smaller), although the narrative discusses them separately. The English yuho also names the single segment two ways, 'high-purity silicon' and 'Crystalline silicon'. Every period, but with no business-line split and a breakdown only at the year end, so 4 as the floor. Source document →
F6Multi-year financial data file (Excel or CSV) downloadable in English0/5
No downloadable data file. The English Financial Highlights page (a PRONEXUS widget) shows HTML tables of sales, operating profit, ordinary profit, net profit, total assets and equity ratio, quarterly for 2022-2026. Earnings Forecast is also HTML. The rendered pages show no Excel or CSV link. The only download is a ZIP batch of the latest tanshin and deck PDFs on the IR top. Checked the IR top, Financial Information, Financial Highlights, Earnings Forecast, the IR Library and FAQ pages.
F7Guidance disclosed in English with the basis explained4/5
By stated policy, SUMCO forecasts only the coming quarter: 'the Group has adopted the policy of disclosing financial results forecasts for the forthcoming quarter only', given the volatility of its market. The English 1H 2026 tanshin gives the nine-month forecast (sales ¥333.0bn, OP -¥6.3bn, net -¥12.8bn) with a previous-against-revised table, the market view by wafer size, and an assumed rate of ¥160/US$. The deck (25 pp, matching the Japanese) adds the 3Q forecast against the 2Q actual, EBITDA margin, depreciation, the OP bridge (depreciation, cost, FX, sales variance) and a yen sensitivity of ¥1.2bn of OP per ¥1. The basis is fully explained, but there is no full-year forecast in either language, and the 5 band asks for one. 4, as the floor. Source document →
F8English financial disclosure current to the latest Japanese filing period5/5
English results for the six months ended 30 June 2026 published 6 August 2026, the same period as the Japanese filing. Source document →
S1Medium-term management plan in English with numerical targets0/5
SUMCO has no medium-term plan with numerical targets in either language. The English Growth Strategy page, the Annual Report 2025 and the yuho section 'Target management indicators and medium- to long-term management strategies' give a qualitative strategy only: focus on 300 mm leading-edge wafers, reorganise 200 mm and smaller, the four-pillar SUMCO Vision. The Japanese 成長戦略 and IR pages are the same. The only numerical targets are the executive-pay KPIs (ROE 10%, EBITDA margin 40%) in the AGM notice, which are not a plan.
S2IR presentations published in English5/5
Presentation - Result for Q2 FY2026 (6 August 2026), 26 pages in English against 26 in the Japanese deck for the same quarter - page for page - with an audio presentation alongside. Source document →
S3English equity-story or investment-highlights page5/5
Two quantified strengths sections in English. The Who We Are page has 'Our Strengths' (as of 31 Dec 2025): sales ¥409.6bn, 30 locations in 8 countries, industry leader in leading-edge logic share, customer satisfaction 85 points or higher, industry leader in patents, and customer awards (TSMC 12 years running, Samsung 5). The Growth Strategy page gives a 'global share of more than 50 percent' in leading-edge logic. The ANNUAL REPORT 2025 opens with a 'SUMCO Profile' at-a-glance: more than 50% leading-edge share, about 3,600 patents, sales and employees by region, an 80.6% overseas sales ratio, and five-year sales, profit and dividends. A dedicated, quantified section, so 5. Source document →
S4Growth drivers identified and quantified in English5/5
The drivers are named and quantified. ANNUAL REPORT 2025 ('AI-related Demand Driving the Semiconductor and Silicon Wafer Markets') gives an AI-semiconductor market CAGR of 28% against 11% for the market as a whole (2024-28), AI server units at a 19% CAGR, AI PCs 26%, AI smartphones 35%, a 300 mm server wafer demand forecast split into leading-edge logic, DRAM/HBM and NAND, and SUMCO's more-than-50% leading-edge logic share. The 2Q 2026 deck updates this: server and server memory demand forecasts (2Q-2025 against 2Q-2026), and server wafer demand of 2,083, 2,275 and 2,488k wafers a month. Drivers with market size, growth and share attached, so 5. Source document →
S5Results-briefing transcripts or Q&A published in English0/5
There is no transcript or Q&A in either language. The English Financial Results page lists, per quarter, the tanshin, the deck and an 'Audio presentation' (c-hotline, with its own English link). The Japanese 決算短信・決算説明会資料 page lists exactly the same three items (決算発表会音声配信), and the Japanese IR Library has no Q&A section either. English 'Points Highlighted' briefing summaries existed to FY2021 and stopped; none since. The Japanese side has none either.
S6Integrated or annual report available in English5/5
ANNUAL REPORT 2025 covering the year ended 31 December 2025, published 26 June 2026 - the current edition for a December year-end - with an English archive back to 2006, alongside Sustainability Report 2026 (125 pages). Source document →
S7Progress against the previous plan, including misses, explained in English0/5
There is no previous medium-term plan to reconcile, in either language; see S1. The nearest thing is the AGM notice's performance-pay table, which sets the ROE and EBITDA-margin objectives (10.0%, 40.0%) against the FY2025 actuals (-2.1%, 27.4%). That is a remuneration calculation, not a plan reconciliation.
G1Corporate governance report available in English3/5
No Corporate Governance Report in English. What the English reader gets instead is the company's own governance section and a Fundamental Policy on Corporate Governance, both current and substantial - but the TSE filing answers a fixed set of questions in a comparable form, and this prose does not, so the reader must go to the Japanese filing for them. Source document →
G2Director biographies in English with tenure, expertise and independence5/5
The English Notice of Convocation of the 27th OGM (6 Mar 2026, 51 pp) profiles all 12 candidates: six directors (Proposal 1) and six Audit & Supervisory Committee directors (Proposal 2), the whole board. Each gets date of birth, shares held, career history and concurrent posts, the reasons for nomination, 'Number of years in office as Director' (e.g. 16, 10, 4 and 2 years), and an 'Independent Director candidate' mark. The notice also states the independence criteria and lists the board after the meeting with independent directors marked. All three elements for every director, so 5. Source document →
G3Board skills matrix published in English5/5
The current skills matrix is in English. The March 2026 AGM notice carries '[Reference] The list of skills ... possessed by each Director following the approval of all proposals': every director against seven skills (Corporate Management, Finance/Accounting, Legal/Compliance, Sales/Marketing, Internationality/Globality, Technology/Manufacturing/IT, HR). ANNUAL REPORT 2025 (June 2026) repeats a Directors' Skills Matrix. Current, so 5. Source document →
G4Executive remuneration structure and its performance linkage explained in English5/5
The English AGM notice's business report gives the whole picture. Structure: basic remuneration, performance-linked cash on semi-annual net profit, and performance-linked stock via a trust (malus and clawback). KPIs and weights for the stock plan: ROE 45%, EBITDA margin 45%, GHG reduction 10%, with the FY2025 objectives against actuals (ROE 10.0% against -2.1%, EBITDA margin 40.0% against 27.4%), and the bonus index result (¥2,584m and -¥14,908m half-years), so no performance pay and a 1:0:0 mix. Amounts by type: 13 directors, ¥341m, all basic. Ceilings: ¥460m, ¥110m and 210,000 points. ANNUAL REPORT 2025 repeats it. Structure, KPIs, weights and amounts, so 5. Source document →
G5AGM notice in English with sufficient lead time to vote4/5
Convocation notice in English published 6 March 2026 (electronic provision from 5 March) for a meeting on 27 March 2026 - 21 days to vote. Re-checked 23 Oct 2026 (G5 voting-site sweep, after the independent audit): the voting website named in the English notice, www.web54.net (Sumitomo Mitsui Trust Bank), is in Japanese only, with no English option, as for ESPEC (6859) and Nitto Boseki (3110). Every proposal in English, but a Japanese-only voting route, so 4. Source document →
G6Shareholder vote results disclosed in English2/5
A Notice of Resolution is published in English, but it is 274 words and reports only that resolutions passed. No vote counts, no approval ratios. An English reader learns the outcome, not the vote. Source document →
G7Cross-shareholdings in English with reduction schedule and rationale3/5
The English Annual Securities Report for FY2025 (Shareholding section) shows no shares on SUMCO's balance sheet held for strategic purposes. Shares held for purposes other than pure investment: unlisted none, listed none; specified investment shares 'Not applicable'; no increases or decreases. The only item is a deemed holding: 688,100 Miraial shares (¥902m) placed in a retirement-benefit trust. Its rationale is stated and reviewed periodically by the board. The holding policy and the board's annual review are set out in English. Re-checked 21 Oct 2026 under v1.1.1, which brings deemed holdings (shares in a retirement-benefit trust whose votes the company directs) into G7. SUMCO's one holding is now in scope: the Miraial deemed holding is disclosed in English with a short rationale and the board's periodic review, but with no reduction target. Policy and numbers without a target, so 3. Source document →
O1English IR section reachable within two clicks of the English homepage5/5
On the English homepage www.sumcosi.com/english/, 'Investor Relations' is a visible item in the top navigation bar and links straight to /english/ir/. One click. Source document →
O2English document links resolve to English documents5/5
Sampled 21 English document links across types and years. All 21 are English, with no CJK text beyond stray characters: 1H and 1Q 2026 tanshin; 1H and 1Q 2026 decks; FY2018 tanshin (Brief Statement) and FY2018 Points Highlighted; FY2008 results (Jan 2009); Annual Securities Report FY2025; Semiannual Report FY2026; ANNUAL REPORT 2025 and Annual Report 2006; 27th AGM notice, notice of resolution and electronically provided matters; FY2026 Interim Business Results; interim dividend notice; subsidiary reclassification notice; personnel notice (Jan 2026); 3Q 2025 correction; Sustainability Reports 2026 and 2023. All English, so 5. Source document →
O3English IR archive free of dead links5/5
The same 21 links, dated 2006 to Sep 2026, on eir-parts.net, sumcosi.com and the S3 bucket. All opened and rendered with page counts (1 to 164 pp). No dead links, so 5. Source document →
O4English IR pages render without blank JavaScript failures5/5
Rendered in Chromium, every page shows its content: the IR top (screenshot: IR news, latest materials, FY2025 key figures, menus), IR Library, Financial Results and Securities Reports (year selectors populate the PRONEXUS lists), Annual Report, AGM materials, Others, IR News, Financial Highlights (HTML tables), Earnings Forecast, IR Calendar, Shareholders Meeting, Stock Information, Analyst Coverage and Q&A. 'Stock Chart' is an outbound link, not an embedded widget. No blank lists or widgets, so 5. Source document →
O5Single page listing all English IR documents by date and type3/5
No single library. The IR Library splits by type into Financial Results (tanshin, deck and audio by year and quarter, dated), Securities Reports (dated), Shareholder Reports (dated), Annual Report (dated), Materials for General Meeting (by meeting number, undated) and Others (timely disclosures, dated). The IR News page is a dated feed of most documents by year back to 2006, but it is untyped and leaves out the AGM notices. Split by type, each mostly dated, so 3, as for the news-feed case at Resonac. Source document →
O6English archive genuinely populated, not an unverifiable shell5/5
A deep archive: tanshin and decks by year from FY2008 to FY2026; annual reports from 2006 to 2025; securities reports FY2018-2026; shareholder reports FY2008-2026; AGM materials from the 11th to the 27th meeting; timely disclosures from 2012; IR News from 2006. Several years across every document type, so 5. Source document →
O7Named English IR contact published3/5
The English Contact page (header link on every page) invites 'questions about our company, our products, and investor relations', points to the IR Library and an Investor Relations Q&A, and links a shared contact form whose inquiry types include 'Inquiry about IR information'. A real IR route, but a shared form rather than a dedicated IR contact. The results header also names Takayuki Komori, General Manager of Public Relations & IR Department, +81-3-5444-3915. Re-checked 23 Oct 2026 after the independent audit; the earlier note read the form as having no IR route. A shared form with an IR option, so 3. Source document →
R1Earnings materials published in English simultaneously with Japanese5/5
The English and Japanese results pages give the same posting date for tanshin and deck every period: 1H 2026 on 6 Aug 2026 in both, 1Q 2026 on 12 May 2026 in both, FY2025 on 10 Feb 2026 in both, 3Q 2025 on 11 Nov 2025 in both. The English tanshin carry TDnet IDs next to the Japanese ones (2864809 against 2864795). The English PDFs were created before release (1H tanshin 4 Aug, deck 6 Aug). Same day, every period, so 5. Source document →
R2Median lag in days between Japanese and English statutory publication5/5
Lags, English against Japanese. 1H 2026 tanshin: 6 Aug / 6 Aug = 0. 1Q 2026 tanshin: 12 May / 12 May = 0 (library dates). AGM notice: both dated 6 Mar 2026 with electronic provision from 5 Mar = 0, going by the documents' own dates (PDF creation: Japanese 19 Feb, English 3 Mar). Annual securities report: Japanese 26 Mar 2026, English 31 Mar 2026 = 5. Corporate Governance Report: no English version = >90. Sorted 0, 0, 0, 5, >90; median 0, so 5. Source document →
R3Timely disclosures published in English5/5
Twelve months to 14 Oct 2026, Japanese IR news list against the English one. Every Japanese timely disclosure has a same-day English counterpart. 11 Nov 2025: 3Q results, dividend forecast revision, forecast-actual difference. 5 Jan 2026: personnel change. 10 Feb: FY2025 results, forecast-actual difference, management changes (two English notices). 19 Feb: year-end dividend and subsidiary reclassification. 12 May: 1Q results and dividend forecast revision. 6 Aug: 1H results and interim dividend. 27 Aug: reclassification completed. The English list also carries the 3Q correction (14 Nov) and the stable-supply plan approval (27 Mar). All, same day, so 5. Source document →
R4English disclosure free of machine-translation accuracy disclaimers5/5
Rendered the English homepage, IR top, Financial Results, Disclaimer, Terms of Use and the governance page. There is no machine- or AI-translation notice and no translation banner. The IR disclaimer covers forward-looking statements and accuracy in general. The documents carry the human-translation 'original shall prevail' note, which belongs to R5. So 5. Source document →
R5English version stated as authoritative, not subordinate to Japanese2/5
The statutory documents carry the 'for reference purposes only ... the original shall prevail' clause (for example the Notice of Resolution of the 27th AGM, 27 Mar 2026), but the English results deck for the second quarter of FY2026 (6 Aug 2026, 25 pages) has only a forward-looking-statements note, without that clause. Re-checked 21 Oct 2026 after the independent audit of 20 Oct; the earlier note said every English document carried it. Some documents, so 2. Source document →
Open a question for the reasoning and the document its score was read from. A zero means no qualifying English materials were located within the stated review scope as of 2026-10-01. Compare this question across companies →
Capital-policy review
Not scored. 1 action has been reviewed; a score out of 100 is published once 3 or more are. The ratings:
Each action is read against the company’s own filings on four checks: was the promise specific, can the steps be traced, were the economics explained, and did it report back against the target. This records the status of selected actions, not an assessment of the company as a whole. How this is scored →
Small-diameter wafer production reorganization
Strategy or target reset · In progress · Decision announced 7 February 2025
SUMCO plans to transfer wafer production from Miyazaki to other domestic plants and Indonesia, end Miyazaki wafer production by 31 December 2026, retain monocrystalline production there and reassign affected employees to 300 mm operations. The FY2025 business report says the reorganization made steady progress, but does not quantify completion, savings, capacity transferred or employee reassignment.
Timeline and sources (2 steps)
- 7 February 2025Miyazaki wafer-production transfer announced SUMCO set an end-2026 completion date, named domestic plants and Indonesia as transfer destinations, and reported a ¥5.8bn FY2024 restructuring charge. Announcement on Reorganization of Small-Diameter Silicon Wafer Production
- 31 December 2025 · announced 4 March 2026FY2025 progress update The business report says SUMCO made steady progress reorganizing production of wafers of 200 mm and smaller, without publishing a percentage complete, transferred capacity, realized savings or employee-transfer count. Notice of Convocation of the 27th Ordinary General Meeting of Shareholders
What management said it would do
On 7 February 2025 SUMCO said it would consolidate production of wafers of 200 mm and smaller by transferring wafer production from Miyazaki to other domestic plants and Indonesia, ending Miyazaki wafer production by the end of 2026 and reassigning affected employees to 300 mm operations.
From the company’s own disclosure · Announcement on Reorganization of Small-Diameter Silicon Wafer Production
What it actually did, and when
SUMCO booked ¥5.8bn of FY2024 structural-reform expense and later said the reorganization made steady progress during FY2025. The reviewed disclosures do not quantify transferred capacity, customer qualification, employee reassignment or completion percentage.
Partly disclosed — a gap remains · Announcement on Reorganization of Small-Diameter Silicon Wafer Production · Notice of Convocation of the 27th Ordinary General Meeting of Shareholders
What it disclosed about the economics
Management cited prolonged weakness in consumer, industrial and automotive demand, structural migration away from 150 mm-and-smaller wafers, and a need to concentrate resources on leading-edge 300 mm products. It quantified ¥4.6bn of impairment and ¥1.2bn of inventory write-down and other expense, but no recurring savings or return hurdle.
From the company’s own disclosure · Announcement on Reorganization of Small-Diameter Silicon Wafer Production
What has happened since
The FY2025 business report says progress was steady while 200 mm-and-smaller shipments remained slow. The August 2026 results expected gradual demand recovery, but neither source gives a reorganization completion bridge or attributable profitability improvement; the end-2026 milestone was still ahead.
Partly disclosed — a gap remains · Notice of Convocation of the 27th Ordinary General Meeting of Shareholders · Results for the Second Quarter of FY2026
The question this leaves open
Investor question: How much production and customer volume has moved, what recurring savings and return improvement justify the ¥5.8bn charge, and will the end-2026 deadline be met? IR preparation: show a dated capacity, qualification, employee and economics bridge.
Our analysis, not a company statement
Balance sheet and capital-policy indicators
A source-backed FY2025 cash, capital-structure and governance reading, separate from the disclosure/follow-through score. It identifies questions, not an investment rating or an excess-cash verdict.
Cash use and returns
SUMCO reports roughly ¥100bn of FY2025 operating cash flow, ¥79.957bn of capital expenditure, ¥7bn of cash dividends and ¥75.2bn of year-end cash and equivalents.
Capital structure
The FY2025 gross D/E ratio was 0.61x, and the group reports ¥56.05bn of new long-term borrowings during the year while capital expenditure remained ¥79.957bn.
Governance of capital decisions
SUMCO's performance-linked stock plan weights ROE and EBITDA margin at 45% each and GHG reduction at 10%. The governance disclosure shows FY2025 objectives of 10.0% ROE and 40.0% EBITDA margin versus actuals of −2.1% and 27.4%, with no performance-linked monetary or stock remuneration paid for the year.
Preliminary and not scored: a single-company reading, reviewed 24 September 2026. Normalized ROE, discretionary cash, ROIC–cost-of-capital spread, project returns, debt maturities, leases and peer context remain unassessed; none enters the live accountability score. Figures are the company’s own reported numbers; a large cash balance is not called excess without a defensible operating reserve and investment plan. Every company with a balance-sheet reading →
Changes to this record
- Research error 23 October 2026 · G5: 5 → 4. Every proposal is in the English notice, but the voting website shareholders use (Sumitomo Mitsui Trust Bank) is in Japanese only.
- Research error 23 October 2026 · O7: 2 → 3. The English Contact page invites investor-relations questions and its shared form has an 'Inquiry about IR information' option: a real IR route, though not a dedicated one.
- Rule change 21 October 2026 · G7: 5 → 3. Under v1.1.1, deemed holdings (shares in a retirement-benefit trust whose votes the company directs) count as cross-shareholdings. SUMCO's one deemed holding is disclosed in English with its rationale, but no reduction target is set.
- Research error 21 October 2026 · R5: 1 → 2. The English statutory documents say the Japanese original prevails, but the English results deck of 6 August 2026 has only a forward-looking-statements note. The earlier note said every English document carried the clause.
- Research error 21 October 2026 · F4: 5 → 4. The English Annual Securities Report is complete except for the independent auditor's report, which it does not include and which is not published separately in English. The earlier note said it was included.
Every change is labelled as a research error, new evidence supplied, improved disclosure or a rule change, with its date and the previous score. Change log →
Scores assess how English information is published, not the quality of the business or its investment value. To report an error or a document we missed, see how to contact us.