The Vig Is the Entire Story
Every dollar bet on DraftKings, FanDuel, BetMGM, or any traditional sportsbook includes a built-in house edge called the vigorish (vig). The standard vig on a -110/-110 line is 4.55%. On parlays, it compounds to 10-30%. On exotic bets, it can exceed 40%. This means before you place a single wager, the sportsbook has already taken its cut. You need to win more than 52.4% of your even-money bets just to break even on standard lines. That is a hurdle rate that the vast majority of recreational bettors never clear.
Kalshi's event contracts on sports outcomes have no explicit vig. The exchange matches buyers and sellers at market-determined prices. Kalshi earns revenue from the spread between yes and no prices, but this spread is set by market makers competing for order flow — not by a house with a structural mathematical advantage. The effective cost of trading a sports outcome on Kalshi is typically 1-2%, compared to 4.55%+ on a traditional sportsbook. Over hundreds of bets, that 2.5-3% difference is the difference between profitability and slow-motion account destruction.
Contract Structure Differences
Traditional sportsbooks offer point spreads, moneylines, totals, props, and parlays. The variety is enormous — a single NFL game might have 500+ available bets. This breadth is both an advantage and a trap. Most of the exotic offerings carry inflated vig because recreational bettors love the long-shot payoffs and do not calculate the implied probability.
Kalshi's sports offerings are more limited but more transparent. Contracts are binary: "Will Team X win?" settles at $1.00 or $0.00. "Will the total points exceed 48.5?" settles at $1.00 or $0.00. The price you pay is the market's implied probability, and you can see every order on the book. There are no hidden margins, no mysterious line movements driven by the house adjusting its exposure, and no limit on winning accounts. That last point deserves emphasis.
Sportsbooks limit winning bettors. If you consistently beat the closing line, DraftKings will restrict your account — lowering your maximum bet from thousands to dollars, or banning you outright. This is the sports betting industry's dirty secret: the business model depends on losers, and winners are literally expelled from the platform. Kalshi does not limit accounts. If you find an edge and exploit it profitably for years, Kalshi benefits from your volume. The incentive structures are fundamentally aligned — Kalshi wants you to trade more, not lose more.
Liquidity and Market Depth
The sportsbook advantage: deep liquidity on major events. You can bet $10,000 on an NFL game at DraftKings without moving the line. You might struggle to deploy $10,000 on the same game on Kalshi without significant price impact. For large bettors, the execution cost of moving the market on a thin Kalshi contract can exceed the vig savings.
The trend is moving in Kalshi's favor. Sports contract volume has grown 500% year-over-year on the platform, and major events (Super Bowl, March Madness, NBA Finals) now see six-figure daily volumes that accommodate most retail bet sizes. For bets under $5,000 on major events, Kalshi's liquidity is sufficient. For niche sports or obscure props, traditional sportsbooks still offer better execution.
Tax Treatment
Here is where prediction markets have a structural advantage that most bettors overlook entirely. Sportsbook winnings are taxed as ordinary income, reported on Schedule 1. You can deduct losses only up to the amount of your winnings, and only if you itemize deductions. Most recreational bettors do not itemize, which means their losses provide no tax benefit.
Kalshi contracts are treated as Section 1256 contracts for tax purposes, similar to regulated futures. This means gains receive the 60/40 tax treatment: 60% of gains are taxed at the long-term capital gains rate (20% max) and 40% at the short-term rate (37% max). The blended rate is approximately 26.8% at the top bracket — compared to 37% for ordinary income from sportsbooks. On $10,000 in annual profits, the tax difference is roughly $1,000. Over a career of sports trading, the tax advantage alone justifies using Kalshi over sportsbooks when both offer the same market.
The Analytics Advantage
Prediction markets provide transparent price history that you can analyze for patterns, inefficiencies, and systematic mispricings. Kalshi's API lets you download historical contract data, build models, and backtest strategies against realized outcomes. Try getting historical odds data from a sportsbook — most guard it jealously or charge thousands for access.
The data transparency creates a compounding advantage. Every bet you place on Kalshi generates data that feeds your future analysis. You can calculate your Brier score (a formal measure of prediction accuracy), identify which sports and contract types you trade most profitably, and refine your approach based on evidence rather than gut feel. Sportsbooks give you a betting history. Kalshi gives you a dataset.
When to Use Each Platform
Use sportsbooks when: You want access to exotic props and parlays that Kalshi does not offer. You are betting on niche sports with no Kalshi contracts. You want to deploy large amounts on major events where sportsbook liquidity is deeper. You value deposit bonuses and promotions (sportsbooks spend billions on customer acquisition).
Use Kalshi when: You are a winning bettor tired of account restrictions. You want lower effective costs on standard bets. You value the 60/40 tax treatment. You want transparent market data for analysis. You are building a systematic approach to sports trading rather than placing recreational wagers.
The optimal approach: Maintain accounts on both. Use sportsbooks for exotic bets where their variety is unmatched and the entertainment value justifies the higher vig. Use Kalshi for standard bets (moneyline, total, binary outcomes) where the cost and tax advantages compound into meaningful edge over time. Check prices on both before every bet — the price differential between a sportsbook implied probability and Kalshi's market price occasionally creates risk-free arbitrage opportunities that the disciplined trader can capture.
The Bottom Line
If you are a recreational bettor who views sports wagering as entertainment, sportsbooks are fine. The vig is the price of convenience, variety, and fun. If you are a serious bettor who tracks results, calculates edge, and treats sports trading as a business, Kalshi is objectively better on cost, tax treatment, account longevity, and data transparency. The market is moving toward exchanges and away from bookmakers. The smart money already has.
