Market TrustClaim ledgerDiligence packet
8%yes · live odds
Do not citeUnder-measured: 1 of 6 pillarsMeasurement certainty Low
Odds via Polymarket public API. Verdict is an experimental market-quality diagnostic, not advice.
-51.0 pts 24h

Part of event: S&P 500 (SPX) Up or Down on August 24? · spx-up-or-down-on-august-24-2026

Market structure and 24h change as reported by Polymarket's public API.

Top of book

Best bid

0.070

Best ask

0.080

Spread

13% of mid

1.00 pts

As reported by Polymarket's public API at 15:10 UTC; top of book, not full depth; per-side depth not shown. The spread is shown against the midpoint of the two quotes above, which is arithmetic on the venue's figures, not a figure the venue reports.

Volume

24h volume

$27,118

Total volume

$28,212

Volume as reported by Polymarket's public API.

Resolution rules

Rules as stated by Polymarket, reproduced verbatim. Convexly has not independently reviewed them and does not endorse them; the rating's resolution-reliability pillar treats rule text as present but not independently reviewed.

This market will resolve to "Up" if the official S&P 500 Index closing price for S&P 500 (SPX) on Monday, August 24, 2026 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day. This market will resolve to "Down" if the official S&P 500 Index closing price for S&P 500 (SPX) on Monday, August 24, 2026 is lower than the official S&P 500 Index closing price for SPX on the most recent prior trading day. E.g., ordinarily, a market on Monday would refer to the previous Friday for its most recent closing price, unless that Friday were a market holiday, in which case it would refer to Thursday, or the next most recent trading day. If the two specified closing prices are exactly equal, this market will resolve 50-50. Note that all figures will be rounded to the nearest cent using standard rounding. If SPX does not trade at all during the regular session, the market will resolve 50-50. If either of the relevant days are shortened (for example, due to a market holiday schedule), the official closing price published by S&P 500 Index for that shortened session will still be used for resolution. If either of the relevant days have no official closing price (for example, due to a trading halt into the market close, system issue, delisting, or other disruption), the market will use the last valid on-exchange trade price of the regular session as the effective closing price. The resolution source for this market is the Wall Street Journal, specifically the Close values published by the WSJ under "Historical Prices". US: https://www.wsj.com/market-data/stocks EMEA: https://www.wsj.com/market-data/stocks/emea ASIA: https://www.wsj.com/market-data/stocks/asiaShow the full rules text

This market will resolve to "Up" if the official S&P 500 Index closing price for S&P 500 (SPX) on Monday, August 24, 2026 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day. This market will resolve to "Down" if the official S&P 500 Index closing price for S&P 500 (SPX) on Monday, August 24, 2026 is lower than the official S&P 500 Index closing price for SPX on the most recent prior trading day. E.g., ordinarily, a market on Monday would refer to the previous Friday for its most recent closing price, unless that Friday were a market holiday, in which case it would refer to Thursday, or the next most recent trading day. If the two specified closing prices are exactly equal, this market will resolve 50-50. Note that all figures will be rounded to the nearest cent using standard rounding. If SPX does not trade at all during the regular session, the market will resolve 50-50. If either of the relevant days are shortened (for example, due to a market holiday schedule), the official closing price published by S&P 500 Index for that shortened session will still be used for resolution. If either of the relevant days have no official closing price (for example, due to a trading halt into the market close, system issue, delisting, or other disruption), the market will use the last valid on-exchange trade price of the regular session as the effective closing price. The resolution source for this market is the Wall Street Journal, specifically the Close values published by the WSJ under "Historical Prices". US: https://www.wsj.com/market-data/stocks EMEA: https://www.wsj.com/market-data/stocks/emea ASIA: https://www.wsj.com/market-data/stocks/asia

Resolution mechanics

Resolution parameters as stated by Polymarket.

Resolved by (UMA adapter)
0x65070BE91477460D8A7AeEb94ef92fe056C2f2A7
Proposer bond
$250 proposer bond
Proposer reward
$1 proposer reward
Stated resolution source
https://www.wsj.com/market-data/stocks

Market Trust diagnostic · v0.2 candidate

S&P 500 (SPX) Up or Down on August 24?

This market is not in the v0.1 daily card set yet. The v0.2 diagnostic scorecard below shows the per-pillar contribution from the latest materializer run, with visible caveats and evidence-status separation.

Why this rating

Why this rating

Composite 53 · Do not cite

Measurement certainty

Low

1 measured · 3 modeled · 2 not assessed

Certainty reflects how much of this market we measured, not how good the market is.

  • CoherenceModeled estimatefixed rules, not a per-market measurementweight 25.0

    No full-provenance CME signal is linked to this condition in the current ledger window; absence of a signal is not proof of coherence.

    • · no linked cme signal in window
    • · absence of signal not proof of coherence
    • · cme signal window days: 7
    • · recent full provenance signals: 23
    50+17.9
  • ExecutabilityModeled estimatefixed rules, not a per-market measurementweight 20.0

    Executability scored as worse-of(spread, depth) from a single orderbook snapshot; the two were merged from the former liquidity + depth pillars to stop double-counting one correlated source.

    • · executability worse of spread depth
    • · spread: top-of-book spread 1.0c
    • · spread: spread is 3% of mid, tight relative to price
    • · spread: pp-band-to-cents-band approximation in effect (depth_5pct_usd/2 per side); per-side decomposition pending substrate work
    15+4.3
  • Resolution reliabilityModeled estimatefixed rules, not a per-market measurementweight 20.0

    Resolution source and rule text are present but not independently reviewed.

    • · resolution metadata present manual review pending
    70+20.0
  • Participant flowNot assessednot yet measured for this marketweight 20.0

    Participant flow inputs exist but do not meet identity-coverage floors; descriptive only.

    • · below publishable sample floor
    • · high participant concentration
    • · high unknown flow share
    • · insufficient scored accounts
    not assessednot assessed
  • Integrity-risk screenNot assessednot yet measured for this marketweight 10.0

    One or more screen indicators flagged at a low level. A reason to look, not a finding about anyone.

    • · top-3 wallets control 82% of notional flow
    • · flow events: 7
    • · distinct wallets: 7
    • · wash round trips: 0
    75not assessed
  • Audit completenessMeasuredweight 5.0

    3 linked artifacts; 0 missing hashes; 0 stale/failing sources.

    • · artifact hashes present
    • · source watermarks healthy
    100+7.1

How it adds up: composite = Σ(score × weight) / Σ(weight) across measured + heuristic pillars only. Pending and data-rights-blocked pillars are excluded from both numerator and denominator. Total contributing weight = 70.0.

Caveat: 2 pillars not assessed yet; the score will recompute as the substrate fills in.

Structural coherence read

The Coherent Markets Engine checks this market's pricing for structural inconsistencies against related markets. Whether a current signal exists, and its construction, is included with Researcher.

See Researcher

Market opened 2026-08-21 · minimum order size 5 shares · price tick size 0.010 · as stated by Polymarket.