Will Bitcoin reach $85,000 in September?47%36.0Will Bitcoin reach $82,500 in September?79%58.5Will Ethereum reach $2,700 in September?75%50.0Will WTI Crude Oil (WTI) hit (LOW) $95 in September?100%17.4Will United Russia (ER) gain the most seats in the next Russian parliamentary election?82%5.0Will Anthropic IPO by October 31, 2026?9%45.0Will Flávio Bolsonaro finish in second place in the first round of the 2026 Brazilian presidential election?70%7.0Will Bitcoin dip to $72,500 in September?10%25.0Will SPD win the most seats in the 2026 Mecklenburg-Vorpommern parliamentary elections?51%12.0Will the price of Bitcoin be above $80,000 on September 19?92%6.9Will Bitcoin reach $90,000 in September?13%9.6US x Iran diplomatic meeting by September 30, 2026?14%9.0Will AfD win the most seats in the 2026 Mecklenburg-Vorpommern parliamentary elections?50%11.0Russia Elections: United Russia Wins Every Region?68%6.5Will the Fed increase interest rates by 25 bps after the October 2026 meeting?55%5.0Anthropic IPO in October?17%40.2
PolymarketMacro / FedUpdated 2m ago

S&P 500 (SPX) Up or Down on September 18?

Last traded probability
100.0%
+34.5 pts
past 24h
Awaiting resolution

The event deadline has passed. This market is awaiting formal resolution, so the price shown is the last traded level, not a live forecast.

Last probability before deadline
100.0%
Event deadline
September 18, 2026 at 4:00 PM ET
Venue status
open
Resolution source
wsj.com

ProbCast Reliability Summary

S&P 500 (SPX) Up or Down on September 18? The last traded Polymarket probability before the deadline was 100.0%. The event deadline has passed. This market is awaiting formal resolution, so the price shown is the last traded level, not a live forecast.

Market data as of
September 18, 2026 at 5:43 PM ET
ProbCast assessment generated
September 18, 2026 at 5:45 PM ET
Source
Polymarket
Event deadline
September 18, 2026 at 4:00 PM ET
Market status
Awaiting resolution
Data updated
2m ago

What this market actually measures

This market will resolve to "Up" if the official S&P 500 Index closing price for S&P 500 (SPX) on Friday, September 18, 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 Friday, September 18, 2026 is lower than the official S&P 500 Index closing price for SPX on …

This summary shows the opening of the venue's official rules. ProbCast has not yet generated an independent plain-English interpretation for this contract — review the full rules before relying on it.

View full official resolution rules

This market will resolve to "Up" if the official S&P 500 Index closing price for S&P 500 (SPX) on Friday, September 18, 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 Friday, September 18, 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 source: wsj.com

Market data

24h volume

$94.2K

Liquidity

$48.6K

Total volume

$94.5K

Category
Macro / Fed
Venue
Polymarket
Open interest
Spread
0.1 pts
Best bid
99.9%
Best ask
100.0%
7-day range
65.5% – 100.0%
Resolves
Sep 18, 2026
Resolution
wsj.com

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