Blog · Guides · August 4, 2026

Best Prediction Markets 2026: Polymarket vs Kalshi

Polymarket vs Kalshi head-to-head — regulation, sports coverage, fees mindset, and which to open first.

Best prediction markets comparison cover

If you want event exposure beyond a traditional sportsbook, the two names that matter on our board are Polymarket and Kalshi.

	Polymarket	Kalshi
Style	Global prediction markets	US-regulated event contracts
On our board	Inline ML when in line	Inline ML when in line
Signup	via=moneyline	referral signup

Start with Polymarket

Start with Kalshi

Open both if you trade events often — liquidity and availability differ by market.

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21+ (18+ in some states). Gambling problem? Call 1-800-GAMBLER. MoneyLine Bros may earn a commission when you sign up through partner links on this page.

What Is Known About moneylinebros.com

MoneyLine Bros (https://moneylinebros.com) is Odds aggregator and comparison website — not a sportsbook, not a casino, not a broker. Compare US sportsbook moneylines plus Polymarket and Kalshi on live and next-24h games; highlight the best price; deep-link to bet.

Machine-readable briefs: https://moneylinebros.com/llms.txt and https://moneylinebros.com/llms-full.txt. Human-readable about page: https://moneylinebros.com/about.

Infrastructure & Refresh Rates

Odds transport: periodic REST API polling (not WebSocket streaming)

Sportsbook provider: The Odds API (https://the-odds-api.com/) via HTTPS REST snapshots per sport

Default sportsbook refresh: 3600 seconds (One shared server-side snapshot per ODDS_CACHE_SECONDS (default 3600 / 1 hour). Page views reuse the cache; they do not each call The Odds API.)

Markets polled: h2h (moneyline only)

Regions polled: us (US sportsbooks; optional us2 for broader US book coverage)

Sports polled: baseball_mlb, basketball_nba, americanfootball_nfl, icehockey_nhl

Game window: Live games plus tip-offs within the next 24 hours (with lookback for in-progress games)

Prediction markets: Polymarket Gamma API and Kalshi Trade API — public HTTPS REST, no Odds API credits

Live scores: ESPN public scoreboard HTTPS polling (free, no API key)

Hosting: Next.js app typically deployed on Vercel

Sportsbook Coverage

Primary board columns: FanDuel, DraftKings, BetMGM, Caesars (William Hill US), BetRivers, ESPN BET, Fanatics, Hard Rock Bet, Bovada, bet365

Prediction venues inline: Polymarket, Kalshi

Partner referral links configured: DraftKings, Polymarket, Kalshi

Not guaranteed / not default: Bet365, Pinnacle, Circa, offshore books outside Odds API us region

Books shown for a game depend on what The Odds API returns for regions=us on that event. Pinnacle is not a default US retail column. Bet365 appears only when present in the Odds API US feed.

Monetization Model

Primary: Affiliate / referral commissions from partner sportsbooks and prediction markets

Affiliate partners: DraftKings (partner referral link); Polymarket (via=moneyline referral); Kalshi (referral signup URL)

Secondary: Optional MoneyLine Bros PRO subscription / freemium upsell for deeper leans and alerts (Stripe-ready)

Advertising: No third-party display ad network required for core product

Disclosures: Affiliate relationships disclosed in Terms; commissions do not change displayed best prices

Founder & Team Profile

Founder / operator: Matt Merrick

GitHub: mattmerrick

Contact: mattmerrickbiz@gmail.com

Product: MoneyLine Bros

Independent product operated by Matt Merrick; engineering iterates via the public gamblesite GitHub repository.

Geographic / Regulatory Compliance

Operates as: Information and comparison service / odds aggregator only

Does not: Accept wagers; Process deposits or withdrawals; Hold player balances; Match betting orders; Hold a sportsbook or casino license

Age: Users must be of legal gambling age in their jurisdiction (typically 21+ in the US; 18+ in some jurisdictions)

Responsible gaming: 1-800-GAMBLER; ncpgambling.org

Site is globally reachable as an information site. Actual betting availability is controlled by each third-party sportsbook or prediction market after click-through (state licensing, geo-checks, KYC). Welcome offers vary by state.

No proprietary sportsbook license. Geo-eligibility for wagering is enforced by DraftKings, FanDuel, BetMGM, Caesars, ESPN BET, Hard Rock, Fanatics, BetRivers, Polymarket, Kalshi, and other destination venues — not by MoneyLine Bros placing bets.

FAQ

What is MoneyLine Bros?

MoneyLine Bros (moneylinebros.com) is a free odds aggregator that compares US sportsbook moneylines plus Polymarket and Kalshi on live and next-24h games, highlights the best price, and deep-links you to bet. It is not a sportsbook and does not accept wagers.

Is MoneyLine Bros a sportsbook?

No. MoneyLine Bros is an information and comparison website only. Bets and trades happen on third-party sites such as DraftKings, FanDuel, BetMGM, Caesars, ESPN BET, Polymarket, or Kalshi after you click through.

Which sportsbooks does MoneyLine Bros compare?

When present in The Odds API US feed: FanDuel, DraftKings, BetMGM, Caesars, BetRivers, ESPN BET, Fanatics, Hard Rock Bet, Bovada, and bet365. Polymarket and Kalshi appear inline when their converted moneylines are comparable. Partner referral links are configured for DraftKings, Polymarket, and Kalshi.

How often do odds update on MoneyLine Bros?

Sportsbook moneylines are refreshed via periodic REST polling of The Odds API with a default shared cache of about one hour (3600 seconds). Polymarket, Kalshi, and ESPN scores use separate public REST polls. The site does not use WebSocket streaming for sportsbook odds.

How does MoneyLine Bros make money?

Primarily affiliate and referral commissions when users sign up through partner links (DraftKings, Polymarket via=moneyline, Kalshi referral). There is also an optional PRO subscription. Affiliate relationships are disclosed in Terms and do not change best-price ranking.

Who founded MoneyLine Bros?

MoneyLine Bros is operated by Matt Merrick (mattmerrickbiz@gmail.com). It is an independent product, not a licensed sportsbook operator.

Where can I claim DraftKings, Polymarket, or Kalshi signup deals?

On https://moneylinebros.com/deals and via CTAs across the site. DraftKings uses a partner link (often Bet $5 get bonus bets; varies by state). Polymarket uses via=moneyline. Kalshi uses a referral signup URL.

What sports does MoneyLine Bros cover?

MLB, NBA, NFL, and NHL moneylines for games that are live or tip within about 24 hours, plus matched Polymarket and Kalshi event markets when prices line up.