Question 1

What is the current probability for "Which companies will be added to the S&P 500 in Q3?"?

Accepted Answer

The contested Kalshi outcomes for "Which companies will be added to the S&P 500 in Q3?" are Venture Global 12%, Cloudflare 6%, Affirm Holdings 3% — 3 of 22 outcomes are already 95%+. Refreshed continuously.

Question 2

When does this market resolve?

Accepted Answer

This event resolves on 9/30/2026.

Question 3

How is the probability calculated?

Accepted Answer

pdata reads the latest market prices directly from kalshi's public API and normalizes them to a 0-100 probability scale. See https://pdata.world/methodology for details on per-platform conventions.

Question 4

Where can I get this data programmatically?

Accepted Answer

The JSON endpoint is https://api.pdata.world/api/v1/events/kalshi/KXSP500ADDQ-26SEP30. An MCP server with 9 tools is available at https://api.pdata.world/mcp. Full agent guide: https://pdata.world/agents.md.