Data Source Deep Verification: J-Quants vs StockAnalysis vs Actual Filings
2026-04-17 01:11 · 3 KB
Time: 01:11
Cross-validated PE ratios by checking actual company filings (決算短信) via J-Quants raw data, then comparing against StockAnalysis and Yahoo Finance.
Key Finding
J-Quants raw data (EPS, NI, shares) is ACCURATE — it comes directly from official TSE filings. The PE discrepancies have 3 distinct causes:
| Cause | Example | Impact | Fix |
|---|---|---|---|
| Split bug | KHI: pre-split EPS ¥394 ÷ post-split price ¥3,187 = 6.1x | PE wrong by split ratio (5x) | Detect split via share count change, adjust EPS |
| Stale filing | Nidec: latest filing is 2Q (Nov 2025), SA has 3Q+ data | PE uses older earnings | Check disclosure date, flag if >3 months old |
| Methodology | Omron: annualized 3Q (51x) vs rolling TTM (42x) | 10-20% gap, both valid | Use StockAnalysis for display, J-Quants for analysis |
Filing-Level Verification
KHI (7012.T) — SPLIT BUG
- Filing: 3Q EPS ¥394, Shares 168M (pre-split, disclosed Feb 9)
- Split: 5:1 on Mar 30, 2026
- Post-split EPS: ¥394 / 5 = ¥78.8 (cumulative 3Q)
- Annualized: ¥78.8 × 4/3 = ¥105.1
- Correct PE: ¥3,187 / ¥105.1 = 30.3x
- J-Quants shows 6.1x (wrong — mixed pre/post split)
- StockAnalysis shows ~25x (different TTM window)
Nidec (6594.T) — STALE FILING
- Filing: 2Q EPS ¥27.2 (disclosed Nov 14, 2025 — 5 months ago!)
- Annualized: ¥27.2 × 2 = ¥54.4
- J-Quants PE: ¥2,306 / ¥54.4 = 42.4x ← mathematically correct given its data
- StockAnalysis: 22x — has newer quarterly data J-Quants doesn't
- Issue: J-Quants filing is 5 months stale, not a calculation bug
Omron (6645.T) — METHODOLOGY DIFFERENCE
- Filing: 3Q cumulative EPS ¥72.9 (disclosed Feb 5)
- Annualized 3Q: ¥72.9 × 4/3 = ¥97.2 → PE 51.2x (matches J-Quants)
- StockAnalysis rolling TTM: PE 41.8x (sum of last 4 quarters)
- Yahoo rolling TTM: PE 34.3x (different quarter inclusion)
- Both are valid — different methodologies yield different PEs
Data Source Reliability
| Source | Raw Financials | PE Ratio | Timeliness | Best For |
|---|---|---|---|---|
| J-Quants | Excellent (official filings) | Buggy after splits | Depends on filing date | Revenue, NI, EPS, margins, cash flow, forecasts |
| StockAnalysis | Good (aggregated) | Good (split-adjusted TTM) | Most current | PE, PB, valuation display |
| Yahoo Finance | Good | Good (slight TTM variance) | Current | Cross-check |
| yfinance | Unreliable for JP | Known errors | Stale | Avoid |
Recommendation
- Display PE in reports: StockAnalysis (split-adjusted, rolling TTM)
- Fundamental analysis: J-Quants raw data (EPS, NI, margins, FCF from actual filings)
- Company forecasts: J-Quants (forward EPS from company guidance, not analyst consensus)
- When PE gap >20%: Investigate — check for splits (share count change), stale filings (disclosure date), or methodology (annualized vs TTM)