What will S&P 500 (SPX) hit by end of December?
The conditions, incentives and evidence that could shape the answer.The question behind the headline
The S&P 500 title mentions December, but its written window begins at market creation. The touch question also differs from predicting the index’s final December close.
At the October 4, 2026 market snapshot, ↓ $7,400 carried a 67% Yes price. Other open contracts included ↑ $8,000 at 54.5%; ↓ $7,200 at 48.5%. [1]
The condition that changes the answer
A finalized Yahoo Finance one-minute SPX high or low must reach or pass the child strike during regular trading hours. If unavailable, the fallback order is WSJ Markets, Google Finance, then MarketWatch. [1]
Creation through the last regular trading close of December 2026. If fallback data is still absent December 31 at 11:59 p.m. ET, use available observations. [1]
Evidence for and against the leading outcome
A qualifying regular-session candle crossing the selected threshold supports Yes regardless of later reversal.
An after-hours indication or a correct year-end direction without the specified touch can leave the contract at No.
The next useful checks are written window rather than title shorthand; regular-session one-minute candles; ordered fallback data sources. The linked primary references make the process and named data source inspectable. [2][3]
A closer look at the market
These child contracts can overlap: different dates, thresholds or people do not necessarily describe mutually exclusive alternatives. Their Yes prices should not be added into a single winner probability, and the highest Yes price is not automatically the most informative question.
The event had approximately $394,813 in total traded volume at observation. That is a record of turnover across this event, not a count of distinct people, a search-volume estimate or proof that every child contract is easy to trade. The analytical quote is fixed to the timestamp shown here; later live prices can differ. [1]
The useful conclusion is conditional: check the exact milestone before interpreting the price as a view on the larger story.
WEIGH BOTH SIDES
What would change the outlook?
↓ $7,400 — Yes
Quoted market evidence: Oct 4, 2026, 09:57 UTC. The live market panel may show a newer observation.
A qualifying regular-session candle crossing the selected threshold supports Yes regardless of later reversal.
An after-hours indication or a correct year-end direction without the specified touch can leave the contract at No.
The next signals to watch
- Written window rather than title shorthand
- Regular-session one-minute candles
- Ordered fallback data sources
The analysis starts from 67% for the Yes side of “↓ $7,400”. A view merely agreeing that this is plausible does not show that the price understates it. The probability, rule and remaining time all have to be compared. [1]
The useful conclusion is conditional: check the exact milestone before interpreting the price as a view on the larger story.
A FEW GOOD QUESTIONS
What else should you know?
What exactly would settle this market?
A finalized Yahoo Finance one-minute SPX high or low must reach or pass the child strike during regular trading hours. If unavailable, the fallback order is WSJ Markets, Google Finance, then MarketWatch. [1]
What is the deadline, and can settlement come later?
Creation through the last regular trading close of December 2026. If fallback data is still absent December 31 at 11:59 p.m. ET, use available observations. [1]
Does the quoted probability show an advantage?
No. 67% is the observed Yes price for “↓ $7,400”, not a verified probability from independent research. A useful assessment needs evidence that changes the expected chance under the exact rules, plus the actual price available at the time. [1]
CHECK THE EVIDENCE
Sources & further reading
- Polymarket — event, child contracts and resolution rules ↗polymarket.com
- finance.yahoo.com — specified data source ↗finance.yahoo.com
- nyse.com — official source ↗nyse.com
Published . AI-assisted, source-linked analysis. We distinguish evidence from interpretation; this article does not establish a trading edge. How we work →
