# How many Grand Slams will Jannik Sinner win in 2026

> 1+ Grand Slam wins leads at 85%, runner-up 68% across 5 winner-take-all outcomes — refreshed 10 min ago.

URL: https://simplefunctions.dev/odds/grandslam
Updated: 2026-05-03T21:05:52.547Z
Category: general
Status: active
Closes: 2026-09-29

## Headline

- Leader: 1+ Grand Slam wins at 85%
- Runner-up: 2+ Grand Slam wins at 68%
- Outcomes: 5 (winner-take-all)
- Venue: Kalshi (5 contracts)
- 24h volume: $1K

## Bound contracts (5)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| 1+ Grand Slam wins | 85¢ | +1pp | $0 | kalshi | /markets/how-many-grand-slams-will-jannik-sinner-win-in-202-kalshi-kxgrandslam-jsin26-1 |
| 2+ Grand Slam wins | 68¢ | +3pp | $129 | kalshi | /markets/how-many-grand-slams-will-jannik-sinner-win-in-202-kalshi-kxgrandslam-jsin26-2 |
| 2+ Grand Slam wins | 35¢ | ±0 | $304 | kalshi | /markets/how-many-grand-slams-will-carlos-alcaraz-win-in-20-kalshi-kxgrandslam-calc26-2 |
| 3+ Grand Slam wins | 28¢ | +1pp | $600 | kalshi | /markets/how-many-grand-slams-will-jannik-sinner-win-in-202-kalshi-kxgrandslam-jsin26-3 |
| 3+ Grand Slam wins | 10¢ | +2pp | $0 | kalshi | /markets/how-many-grand-slams-will-carlos-alcaraz-win-in-20-kalshi-kxgrandslam-calc26-3 |

## 30-day trajectory

| Day | 1+ Grand Slam wins | 2+ Grand Slam wins | 2+ Grand Slam wins |
|---|---|---|---|
| 2026-04-08 | 73 | 37 | — |
| 2026-04-10 | 81 | 38 | 78 |
| 2026-04-19 | 76 | 39 | — |
| 2026-04-20 | 76 | 39 | 69 |
| 2026-04-24 | 84 | 61 | 46 |
| 2026-04-26 | — | 63 | 41 |
| 2026-04-29 | — | 72 | 36 |
| 2026-05-02 | 86 | — | 34 |
| 2026-05-03 | — | — | 34 |

_26 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-04-26 · 3+ Grand Slam wins +8pp 17→25¢ · kalshi
- 2026-04-28 · 2+ Grand Slam wins −6pp 41→35¢ · kalshi
- 2026-04-30 · 2+ Grand Slam wins −4pp 36→32¢ · kalshi
- 2026-05-02 · 3+ Grand Slam wins +3pp 23→26¢ · kalshi
- 2026-04-27 · 2+ Grand Slam wins +3pp 63→66¢ · kalshi

## Analysis

The 42% probability reflects market expectations that Jannik Sinner will win at least one Grand Slam tournament in 2026. This estimate is driven primarily by Sinner's recent performance trajectory—he won the Australian Open in January 2026 and has demonstrated consistent ability to compete at the sport's highest level. The probability could shift based on his results at the remaining three major tournaments: the French Open (May-June 2026), Wimbledon (June-July 2026), and the US Open (August-September 2026). Additionally, injury status and form throughout the season would materially impact whether he secures a second or subsequent major title. The gap between venues (Kalshi at 42% vs. Polymarket at 35%) suggests some disagreement about whether his Australian Open victory constitutes sufficient evidence of consistent Grand Slam capability this year, or whether it represents an outlier performance.

### Key factors

- Sinner has already won one Grand Slam in 2026 (Australian Open in January), making the 'at least one' threshold already met if that event counts toward the contract specifications
- His surface-specific performance, particularly on clay at the French Open and grass at Wimbledon, will provide concrete data on his adaptability across different court types
- Injury history and tournament participation rate through May-September 2026 will determine exposure to remaining opportunities
- Head-to-head matchup outcomes against other top-ranked players at each remaining Grand Slam serve as direct indicators of competitive position
- Polymarket's lower 35% probability versus Kalshi's 42% may reflect different contract definitions regarding whether the Australian Open win already satisfies the condition

## Methodology

Headline is the **leader's price**, not an arithmetic mean — averaging disjoint winner-take-all outcomes is meaningless. Per-outcome prices come from the venue's last-traded mid; cross-venue values are simple means across contracts on each venue.

## How to use this data

- HTML: https://simplefunctions.dev/odds/grandslam
- JSON: https://simplefunctions.dev/api/public/odds?slug=grandslam

## License

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