S&P 500 (SPX) Opens Up or DownPolymarket historical data and price history
S&P 500 (SPX) Opens Up or Down: a Polymarket indices series with markets recurring daily. Marketlens has captured 134 markets since March 2, 2026, of which 133 resolved, with $3.0M in traded volume. Every market's order book is stored in full: periodic L2 snapshots plus every individual price change with a millisecond timestamp, alongside trades, candles, and the final resolution outcome.
For the indices archive as a whole, see Polymarket price history.
Data as of 2026-09-17 · Polymarket series SPX Open Daily Up or Down · slug spx-open-daily-up-or-down
Resolution outcomes
Outcomes across 132 resolved markets with a recorded winning outcome. Settlement in the archive is by winning outcome, not by final traded price.
Markets in this series
The most recently resolved of 134 markets.
Backtest this series
from marketlens import MarketLens
client = MarketLens()
result = client.backtest(
MyStrategy(), "spx-open-daily-up-or-down",
after="2026-09-10", before="2026-09-18", initial_cash=1_000,
)
result.show() # inspect the run in the dashboardAvailable datasets
Common questions
How many S&P 500 (SPX) Opens Up or Down markets are in the archive?
134 markets from March 2, 2026 through September 17, 2026, of which 133 have resolved and 1 are active.
What data exists for each S&P 500 (SPX) Opens Up or Down market?
Full L2 order book history (snapshots plus every price change at millisecond resolution), individual trades, OHLC candles, and the resolution outcome. All of it is queryable by the series slug "spx-open-daily-up-or-down" through the API and Python SDK, or downloadable as Parquet.
How often do S&P 500 (SPX) Opens Up or Down markets resolve Up?
Of 132 resolved markets with a recorded outcome, 75 resolved Up (56.8%) and 57 resolved Down.
How much does a typical S&P 500 (SPX) Opens Up or Down market trade?
Average traded volume is $36.0K per market, $3.0M across the series.
Can I backtest strategies on S&P 500 (SPX) Opens Up or Down?
Yes. Pass the slug "spx-open-daily-up-or-down" to client.backtest() in the Python SDK. Execution mode replays every market's order book tick by tick and fills simulated orders against real historical depth with queue priority, latency, and fee modelling; Alpha mode replays one bar per market for slower signals over long windows.
Related series: S&P 500 (SPX) Up or Down, Russell 2000 Daily Up or Down, Dow Jones (DJIA) Up or Down, Nasdaq 100 (NDX) Up or Down, Hang Seng (HSI) Up or Down, Nikkei 225 (NIK) Up or Down, or all indices series.
Try it
Replay S&P 500 (SPX) Opens Up or Down tick by tick
The free tier includes 1M rows per day with full API and full archive access, no card required.
$ pip install marketlens