What do prediction markets say about the S&P 500?
By Faizan Ahmad. Updated .
The S&P 500 outlook on Tradytics Probabilities shows it at a glance: three months of daily candles, then a fan of where Kalshi and Polymarket put the index at the next close, Friday, month end, three months and year end, darkest where people put the most weight, with jobs, CPI and Fed dates marked on the time line. It reads every live finance question on both venues, is built on an archive of 5.95 million markets back to June 2021, and is free at tradytics.com/probabilities.
The five dates
| Date | What it answers |
|---|---|
| Next close | Where the index lands at 4pm, from the day's close questions |
| Friday | Where the week ends |
| Month end | Where the month ends |
| Three months | Where the quarter ahead ends |
| Year end | Where the year ends |
One chart shows both where people expect the index at each date and how spread out they are about it.
How to read the fan
- The shade. Darkest where people put the most weight, fading toward the levels they think unlikely.
- The width. How far people think the index can travel by that date.
- The release marks. Jobs, CPI and Fed dates sit on the time line, so a widening band can be read against the releases inside it.
How good the read is
Tradytics' study of its archive found that on S&P 500 4pm closes, people's chances match what same-day options price, strike by strike: an average gap of 4 to 6 points, and a range for the close 1.01 to 1.03 times the options'. Read an hour before the close, Kalshi's S&P 500 questions came true about as often as priced: 15% happened 13.0% of the time, 45% happened 44.6% and 96% happened 95.8%. The page scores itself too: for the index close questions it shows where people put the close at 10 AM in each of the last 30 sessions against where it actually closed. The full study: how accurate prediction markets are.
Beyond the S&P 500
- Nasdaq. Its close questions, free alongside the S&P 500.
- Every finance question. Index ranges, single stocks and earnings beats, each a row with people's median and the move it implies, and a page with the chance of every outcome.
- Earnings. Each beat question beside the stock's past report-day moves.
Whether these chances say more than options do: does Polymarket predict the stock market.
Plans and the API
| Free | Plus | Pro | |
|---|---|---|---|
| S&P 500 and Nasdaq outlook | Yes | Yes | Yes |
| Every stock and earnings question | Yes | Yes | |
| Prediction market API | Yes |
The same chances and the settled archive are in the prediction market data API on the Pro key, and in the backtester, where a Kalshi market can drive a stock or options strategy. Everything on the page: Tradytics Probabilities.
Common questions
Where can I see Kalshi and Polymarket's S&P 500 outlook?
On Tradytics Probabilities, free: the next close, Friday, month end, three months and year end in one fan chart.
Are Fed and CPI dates on the chart?
Yes. Jobs, CPI and Fed dates are marked on the S&P 500 time line.
Is the outlook a price target?
No. It is people's chances for each level on each date, drawn as a fan.
Do prediction markets see the S&P 500 close better than options?
No. On index closes the two price the same chances.