US30 vs SPX500 by session
Point values make Dow and S&P range numbers look incomparable. We aligned their Dukascopy index-CFD bid histories and used percentage range, while keeping points, matched counts, closed windows, and source gaps visible.
The measured answer
Across 718 matched days, US30’s median daily percentage range was 1.231% versus 1.358% for SPX500. US30’s ratio-of-medians result was 9.3% lower, and it had the larger normalized range on 31.5% of matched days.
Exact sources, gaps, and fingerprints
The Phase 3 analyzer read the same binary files served by FXAbsolute. It validated every timestamp and OHLC row, calculated each file’s SHA-256, and published both successful and excluded coverage counts before producing the findings.
Jan 4, 2021–Jul 31, 2026. Unmatched dates and under-covered periods were excluded; no values were filled.
Dukascopy index-CFD historical bid prices · bid prices
- UTC coverage bounds
- Jan 3, 2021–Aug 3, 2026
- Days with any candles
- 1,032 of 1,456 eligible days (70.9%)
- Qualified daily samples
- 1,023; 9 additional observed days failed the daily threshold
- Structural validation
- Header length matches · 0 malformed OHLC · 0 duplicates · 0 out-of-order · 0 off-minute
- Largest recorded gap
- 120.02 hours after Dec 14, 2022
- Repository provenance record
scripts/refetch_thin_assets.mjs· instrumentusa30idxusd- SHA-256
cf90bdd1d326572d9dc58a8e09087b5f93d9c429a93a23e812e303ec0de40115
Dukascopy index-CFD historical bid prices · bid prices
- UTC coverage bounds
- Jan 4, 2021–Aug 3, 2026
- Days with any candles
- 1,072 of 1,456 eligible days (73.6%)
- Qualified daily samples
- 1,061; 11 additional observed days failed the daily threshold
- Structural validation
- Header length matches · 0 malformed OHLC · 0 duplicates · 0 out-of-order · 0 off-minute
- Largest recorded gap
- 192.02 hours after Mar 9, 2021
- Repository provenance record
scripts/refetch_thin_assets.mjs· instrumentusa500idxusd- SHA-256
ba02fab257d76a3427619fda214ba0238bb7a7da223baef0ccea627376f8bb87
Proof scope: the hashes identify the exact bytes measured, and the JSON exposes the displayed aggregates. This proves the reported calculations from these files. It does not prove complete calendar coverage, perfect upstream feeds, causal relationships, future regimes, or trading profitability.
Where the difference appeared
Every comparison uses percentage range as the headline measure and retains the native-unit median for chart scale. A closed or under-covered window is labeled unavailable rather than assigned a zero.
| UTC window | Matched blocks | US30 median | SPX500 median | A/B ratio | US30 higher | Range correlation |
|---|---|---|---|---|---|---|
| 00:00–03:59 UTCAsia open | 716 | 0.255%94.14 points · CI 0.24%–0.27% | 0.297%14.56 points · CI 0.28%–0.319% | 0.858× | 16.1% | 0.972 |
| 04:00–07:59 UTCAsia–London handoff | 716 | 0.271%101.32 points · CI 0.256%–0.288% | 0.312%15.36 points · CI 0.288%–0.329% | 0.87× | 18.6% | 0.975 |
| 08:00–11:59 UTCLondon morning | 719 | 0.367%138.02 points · CI 0.348%–0.386% | 0.394%19.05 points · CI 0.368%–0.421% | 0.933× | 34.4% | 0.933 |
| 12:00–15:59 UTCLondon–New York overlap | 716 | 0.797%304.11 points · CI 0.756%–0.833% | 0.835%40.61 points · CI 0.806%–0.871% | 0.954× | 43% | 0.929 |
| 16:00–19:59 UTCNew York afternoon | 695 | 0.68%255.5 points · CI 0.636%–0.732% | 0.748%36.5 points · CI 0.712%–0.806% | 0.909× | 27.8% | 0.981 |
| 20:00–23:59 UTCLate UTC | 0 | No qualifying paired blocks; no zero-volatility value was imputed. | ||||
SPX500 was modestly wider after normalization
Raw points—469.69 points for US30 and 67.66 points for SPX500—cannot answer which index moved more relative to price. Normalized medians were 1.231% and 1.358%. Their daily range-size correlation was 0.954.
The gap narrowed in the overlap block
From 12:00–15:59 UTC, US30’s median was 0.797% and SPX500’s was 0.835%. The 0.954× ratio was the closest session result, and US30 was higher in 43% of matched blocks.
Strong co-variation is not sameness
The paired daily range correlation of 0.954 indicates large-range days often coincided. Yet US30 exceeded SPX500 on only 31.5% of days, demonstrating that correlation and relative scale answer different questions.
Coverage limitation
US30 contained candles on 70.9% of eligible weekdays inside its bounds; SPX500 covered 73.6%. Only 718 common qualified dates entered the headline. The feeds are index CFDs, not exchange prints.
Latest qualifying regime: normal
On Jul 31, 2026, the trailing median of the latest 20 qualifying daily percentage ranges was 1.194%. For US30, low is at or below 0.963%, high is above 1.458%, and values between are classified normal.
These are within-market retrospective quartiles. A “high” regime for one market is not numerically equivalent to a “high” regime for another, and the label is not a forecast.
Latest qualifying regime: normal
On Jul 31, 2026, the trailing median of the latest 20 qualifying daily percentage ranges was 1.078%. For SPX500, low is at or below 0.931%, high is above 1.677%, and values between are classified normal.
These are within-market retrospective quartiles. A “high” regime for one market is not numerically equivalent to a “high” regime for another, and the label is not a forecast.
How Phase 3 was measured
(maximum high − minimum low) ÷ period open × 100. Native pips, points, or dollars remain published beside it.Reproduce the public report with npm run analyze:seo:phase3. Download the complete Phase 3 evidence JSON.
Limits before strategy testing
High–low range does not preserve the order of prices within a block, and range-size correlation is not return correlation. Wider movement can increase opportunity and risk simultaneously. These findings do not include entries, exits, spreads, slippage, financing, contract specifications, or a profitability model.
Replay the matched markets
Translate the distribution into a precise hypothesis with fixed windows, risk normalization, costs, and exit rules.
Questions this evidence can answer
Was US30 or SPX500 more volatile after normalization?
SPX500 had the higher matched daily median: 1.358% versus 1.231% for US30.
Which session made US30 closest to SPX500?
12:00–15:59 UTC produced the highest US30-to-SPX500 median ratio at 0.954×.
How correlated were their daily range sizes?
The Pearson correlation of matched daily percentage-range sizes was 0.954. This is not return correlation.
Are these official Dow and S&P cash-index bars?
No. The repository fetch records identify Dukascopy index-CFD bid-price instruments. The page does not present them as exchange prints.