St. Louis Cardinals vs Chicago Cubs Prediction Market Odds, August 15, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
â–¶Cardinals | +1.5 56%77% | O 9.5 44%46% | 39%39% | 39% Kalshi |
â–¶Cubs | -1.5 44%23% | U 9.5 56%54% | 63%62% | 63% Kalshi |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
â–¶St. Louis Cardinals | +1.5 | O 9.5 | 39% Kalshi | |
â–¶Chicago Cubs | -1.5 | U 9.5 | 63% Kalshi |
Chicago is the 62c favorite at Wrigley Field, and Kalshi and Polymarket are quoting the identical number on both sides (62c Cubs, 39c Cardinals), so there is no cross-platform disagreement to trade here. The Cubs (72-51, 36-24 at home) took game one of this series 3-0 on August 14 and sit 3.5 games behind Milwaukee in the NL Central. St. Louis arrives at 61-61 and 14 games back, sending Michael McGreevy (4-9, 3.64 ERA) against Matthew Boyd (8-1, 3.50 ERA). The live board above carries the current prices across every line on the game.
Chicago at 62c implies a 62% win probability, which is a wider margin than the two starting ERAs justify on their own. Boyd carries a 3.50 ERA and an 8-1 record, McGreevy a 3.64 ERA and a 4-9 record, a 0.14 gap in run prevention attached to a seven-game gap in decisions. The market is pricing the lineups and the venue, not the arms. The Cubs are 36-24 at Wrigley Field and 8-2 over their last ten games; the Cardinals are 29-27 on the road and coming off a 3-0 shutout loss in game one of this series on August 14.
Cardinals vs Cubs Market Context
The moneyline is the cleanest read on the board. Chicago prices at 62c on Kalshi and 62c on Polymarket, with St. Louis at 39c on both venues. The one cent of overround across the pair is normal exchange vig, and the exact agreement between two independent order books is unusual enough to be worth naming: when Kalshi and Polymarket land on the same number to the cent, there is no relative-value read available, only a directional one.
Movement has been minimal. The Cubs opened the overnight snapshot window at 63c and have settled at 62c, a one-cent drift that qualifies as a held line rather than a move. Nothing in the intraday series suggests late information has hit the market. Volume is concentrated on the favorite side, with roughly $6.2K traded on the Chicago contract against roughly $1.5K on St. Louis.
The run line tells you how the market splits its 62%. Chicago at -1.5 prices at 43c (42c Kalshi, 44c Polymarket), meaning the market gives the Cubs about a 43% chance of a multi-run win and roughly a 19% chance of winning by exactly one. St. Louis at -1.5 sits at 29.5c. That is a favorite the market expects to win, but not to run away.
The total is priced tight to the middle. Over 8.5 runs trades at 58c (59c Kalshi, 57c Polymarket), over 9.5 at 46.5c, and over 10.5 at 40.5c. Interpolating those three points puts the market's fair total just under 9.5 runs, a slightly under-leaning read on a Wrigley afternoon. The first-five-innings ladder agrees: over 4.5 runs through five sits at 56.5c and over 5.5 at 44.5c, so the market expects roughly five runs on the board by the midpoint. A run in the first inning prices at 52c (51c Kalshi, 53c Polymarket).
The strikeout ladder on Boyd is the sharpest starter market on the board. Four-plus strikeouts trades at 67c, five-plus at 45c, six-plus at 21c. That is a steep drop from five to six, and it prices Boyd as a starter the market expects to work into the fifth or sixth without a high-volume punchout game. On the position-player side, Pete Crow-Armstrong at 1+ hits prices at 74c and Alex Bregman at 1+ hits at 68c, the two highest-confidence contact markets Chicago has listed.
The standings stake is asymmetric. Chicago at 72-51 is chasing Milwaukee (75-47) at 3.5 games back with the division still live, so every home game against a sub-.500 opponent carries real leverage. St. Louis at 61-61 and 14 games out is playing for position rather than a race, which is part of why the market is comfortable at 62c despite a competent McGreevy start being on the table. For the other half of the division picture, the Brewers board from August 14 shows how the market has been pricing the leader.
When the Cardinals vs Cubs Market Resolves
The moneyline resolves to the team that wins the game at Wrigley Field on August 15, 2026, first pitch scheduled for 2:20 PM ET. Kalshi and Polymarket both settle on the official final score once the game is called complete. The run line and totals settle on that same final score, and the first-five-innings markets settle on the score after the top and bottom of the fifth are complete.
Key Cardinals vs Cubs Catalysts
Boyd vs McGreevy: Boyd (8-1, 3.50 ERA) and McGreevy (4-9, 3.64 ERA) are 0.14 apart in ERA, so the 62c-39c split is driven by lineups and venue, not by the starting pitching gap.
Wrigley home split: Chicago is 36-24 at home against 36-27 on the road, and St. Louis is 29-27 away from Busch Stadium.
Cross-platform agreement: Kalshi and Polymarket quote the moneyline identically at 62c and 39c, with the widest gap anywhere on the board sitting at 2c.
Total priced under 9.5: Over 8.5 at 58c and over 9.5 at 46.5c bracket a market fair total just under 9.5 runs.
Boyd strikeout ladder: 4+ strikeouts at 67c and 6+ at 21c price a start expected to reach the fifth or sixth without a high-strikeout line.
Division leverage: Chicago is 3.5 games behind Milwaukee at 72-51; St. Louis is 61-61 and 14 games back.
Related Cardinals vs Cubs Markets
Game one of this series is on the board at Cardinals vs Cubs, August 14, where Chicago won 3-0. The Cubs' prior series is at Cubs vs Nationals, August 13, and the Cardinals' last road set before this one is at Phillies vs Cardinals, August 12. Every game on the slate, with live cross-platform prices, is on the MLB prediction market hub.
Resolution Criteria
The moneyline resolves to the team that wins the game between the St. Louis Cardinals and the Chicago Cubs at Wrigley Field on August 15, 2026, scheduled for 2:20 PM ET. The winning team's contract pays $1 per share and the losing team's contract resolves to $0. The run line (-1.5 or -2.5) and the game total settle against the official final score as published by MLB, and the first-five-innings markets settle on the score after five complete innings. If the game is suspended, shortened, or postponed, Kalshi and Polymarket apply their own venue-specific rules: a game called official after five innings (four and a half with the home team leading) generally settles on the score at that point, while a postponement past the scheduled date typically voids the contract or rolls settlement to the completion date depending on the platform.
Key Factors
- Matthew Boyd (8-1, 3.50 ERA) vs Michael McGreevy (4-9, 3.64 ERA), a 0.14 ERA gap behind a 23c moneyline gap
- Chicago is 36-24 at Wrigley Field; St. Louis is 29-27 on the road
- Kalshi and Polymarket agree to the cent on the moneyline (62c Cubs, 39c Cardinals)
- Game total priced just under 9.5 runs (over 8.5 at 58c, over 9.5 at 46.5c)
- Boyd strikeout ladder: 4+ at 67c, 5+ at 45c, 6+ at 21c
- Chicago at 72-51 sits 3.5 games behind Milwaukee in the NL Central; St. Louis is 61-61
What are the current Cardinals vs Cubs odds?
As of August 15, 2026, the Chicago Cubs are the 62c moneyline favorite and the St. Louis Cardinals are at 39c. Both Kalshi and Polymarket are quoting the identical numbers on each side.
Who is favored in Cardinals vs Cubs on August 15, 2026?
Chicago is favored at 62c, an implied 62% win probability, playing at home at Wrigley Field. The Cubs are 72-51 overall and 36-24 at home; the Cardinals are 61-61 and 29-27 on the road.
Who are the probable starting pitchers?
Matthew Boyd (8-1, 3.50 ERA) starts for the Chicago Cubs and Michael McGreevy (4-9, 3.64 ERA) starts for the St. Louis Cardinals. The 0.14 ERA gap is far narrower than the 23c gap between the two moneyline prices.
Where can I trade the Cardinals vs Cubs market?
The game trades on both Kalshi and Polymarket. Kalshi lists the deeper board here, including run lines, team totals, first-five-innings markets, and player props such as the Boyd strikeout ladder at 4+ strikeouts for 67c.
What is the Cardinals vs Cubs total and run line?
Over 8.5 runs trades at 58c and over 9.5 at 46.5c, which puts the market's fair total just under 9.5 runs. Chicago at -1.5 prices at 43c and St. Louis at -1.5 at 29.5c.
When does the Cardinals vs Cubs market resolve?
It resolves when the game goes final at Wrigley Field on August 15, 2026, with first pitch scheduled for 2:20 PM ET. Watch the Boyd strikeout ladder and the first-inning run market at 52c for early signals once lineups post.