Correction and editorial revision — 23 October 2026: This retrospective replaces the earlier mixed-time narrative with dated provider observations. The article called one mixed-time snapshot a volatility regime shift and misstated the Korean return. The earlier causal explanations and trading implications are withdrawn; their removal is not a finding that every cited event was false. Historical closing observations can differ from the intraday quotes used in the earlier version.
This archive review uses observations available in the retrieved daily history on or before 2026-09-10. Each market has its own closing time. The question is: How Different Were the Daily and Five-Session VIX Moves?
What changed in the calculation
- For KOSPI, the archived input reported +1.14%. Matching its quoted value to 2026-09-10 and comparing with 2026-09-09 gives -0.25% in the provider daily series.
The comparison above concerns the archived input and dated daily history. The table below uses a single stated cutoff with each instrument’s own preceding observation; it does not assert simultaneous prices. For the yield proxy, percentage changes in the quote are distinct from basis-point changes and from bond returns.
The measured comparison
VIX moved from 16.46 on 2026-09-09 to 17.84 on 2026-09-10. That is +1.38 index points and +8.38% relative to its earlier level. The two units are not interchangeable. Across five observation intervals from 2026-09-03, the index change was +24.58%. VIX history.
The S&P 500 changed -0.58% over its latest interval and -0.98% over five intervals. A VIX change is not a stock-market return or a count of protective options held. A claim about a new regime requires a defined historical test; the short comparison here does not supply one. It also does not identify which institutions added or removed hedges.
Reproducing the longer comparison
For VIX, the five-interval baseline is 14.32 on 2026-09-03; the endpoint is 17.84 on 2026-09-10. The calculation is (endpoint ÷ baseline − 1) × 100 = +24.58%. This uses the endpoints directly rather than adding rounded daily percentages. Five observations need not correspond to one calendar week when a market is closed.
Source-linked daily observations
| Series | Previous date | Previous value | Date | Value | Change | Time zone |
|---|---|---|---|---|---|---|
| KOSPI (^KS11) | 2026-09-09 | 7,051.64 | 2026-09-10 | 7,033.92 | -0.25% | Asia/Seoul |
| S&P 500 (^GSPC) | 2026-09-09 | 7,636.36 | 2026-09-10 | 7,591.70 | -0.58% | America/New_York |
| Nasdaq Composite (^IXIC) | 2026-09-09 | 26,253.34 | 2026-09-10 | 26,081.72 | -0.65% | America/New_York |
| US 10-year yield proxy (^TNX) | 2026-09-09 | 4.837 | 2026-09-10 | 4.944 | +10.7 bp | America/Chicago |
| WTI futures (CL=F) | 2026-09-09 | 96.05 | 2026-09-10 | 102.48 | +6.69% | America/New_York |
| Gold futures (GC=F) | 2026-09-09 | 4,460.70 | 2026-09-10 | 4,407.30 | -1.20% | America/New_York |
| USD/KRW (USDKRW=X) | 2026-09-09 | 1,339.21 | 2026-09-10 | 1,339.17 | -0.00% | Europe/London |
| USD/JPY (USDJPY=X) | 2026-09-09 | 153.48 | 2026-09-10 | 153.57 | +0.06% | Europe/London |
| VIX (^VIX) | 2026-09-09 | 16.46 | 2026-09-10 | 17.84 | +8.38% | America/Chicago |
Scope and limitations
Returns are calculated before rounding from Yahoo Finance daily history, not independently verified exchange settlement records. Index values are in points; the yield proxy is quoted in percent; currency quotes are local units per US dollar; gold and WTI futures are dollars per ounce and barrel. Futures-series changes can reflect contract rolls and are not a continuously held contract’s investment return. These are retrospective observations, not live prices or a reconstruction of every intraday quote available to the original author.
For the underlying method, see the trading-session and return guide. This page retains its original address for correction transparency. The title and text now reflect the narrower evidence available; the old URL wording should not be treated as a current claim. No trading instruction is retained.
