95% — Top USA Song on Spotify on Apr 21, 2026
Leader: Billie Jean at 95% · Kalshi 95% · 2 contracts · $2 volume · low confidence
Updated 2026-06-26 09:42:32 UTC

Tracks the leading outcome in a winner-take-all prediction market set with 2 outcomes.

Why this matters:
This probability reflects the likelihood that a particular song will rank as the top track on Spotify's USA charts on April 21, 2026. At 88%, the market is expressing high confidence in a specific outcome, though the identity of that song is not specified here. The current level likely reflects either strong recent performance data showing one song's dominance, or limited information causing the market to anchor on a base rate. The main uncertainty factors include competing releases in the weeks leading up to that date, streaming trends that could shift listener preferences, and potential viral or surprise chart entries. The resolution point is fixed—Spotify's official USA chart ranking for that specific date will definitively settle the contract. Key drivers of probability movement would include chart performance through early 2026, new major artist releases, and shifts in streaming velocity as the date approaches.

Key factors:
- Spotify's USA daily top song rankings for the 60 days prior to April 21, 2026 will show which track is trending toward that date
- Major scheduled music releases from top artists between now and April 2026 could displace current leaders or establish new frontrunners
- Year-to-date and March 2026 streaming velocity for the leading candidate will indicate momentum heading into the resolution date
- Historical chart volatility patterns show how frequently the #1 song changes, informing whether 88% confidence is calibrated to normal churn
- Any artist announcements of surprise releases or high-profile promotional campaigns in early April 2026 could shift the leading contender

Contracts:
- Top USA Song on Spotify on Jun 26, 2026?: Billie Jean — 95¢ Kalshi $1 (weight 49%)
- Top USA Song on Spotify on Jun 26, 2026?: Choosin' Texas — 20¢ Kalshi $1 (weight 51%)

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## Methodology

SimpleFunctions aggregates live YES-side prices from Kalshi and Polymarket contracts bound to this question. For binary topics the headline is the liquidity-weighted mid-price (weight = log(1 + 24h volume) × freshness, where freshness is 1.0 if updated <24h, 0.7 if <7d, 0.4 otherwise). For multi-outcome (winner-take-all) topics the headline is the current leader's price — disjoint outcomes are never arithmetically averaged. Snapshots refresh every 5 minutes during market hours.

## SF Signal

- SF Index, regime, and 30d Brier calibration are computed separately and surfaced at https://simplefunctions.dev/admin/calibration.
- No SimpleFunctions index / regime / calibration signal is bound to this topic yet — the headline above is market-derived only.

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*Last verified: 2026-06-26T09:20:49.465Z*

By SimpleFunctions — https://simplefunctions.dev/

Cite as: "95% per prediction markets (SimpleFunctions, June 2026)"
Canonical: https://simplefunctions.dev/answer/spotifyd
Full data: https://simplefunctions.dev/api/public/query?q=Top%20USA%20Song%20on%20Spotify%20on%20Apr%2021%2C%202026
Provider: SimpleFunctions — https://simplefunctions.dev