The five venue chapters gave you portraits; this chapter is the desk reference—how money, engines, fees, limits, clocks, and regulation differ when you plug real frictions into expected value or ask whether a gap is tradable arbitrage. Numbers below are illustrative tiers from common public descriptions; pull current fee schedules and customer agreements before you size. Products change after elections, enforcement actions, and protocol upgrades.
One matrix, five columns
| Dimension | Polymarket | Kalshi | PredictIt | Manifold | Augur |
|---|---|---|---|---|---|
| Money | USDC crypto | USD regulated | USD (capped academic frame) | Mana / optional real | On-chain collateral |
| US retail | Geo/KYC; evolves | Regulated pathway | US-focused; rule-constrained | Global web; light KYC on real | Wallet permissionless |
| Engine | Hybrid pool + book on hits | CLOB-first | Thin retail book | LMSR-style curves | On-chain tokens + sets |
| Typical friction | Trade fee + gas + pool slip | Per-contract fees + spread | Profit fee + wide spread | Low on mana | Gas + protocol fee |
| Scale limit | Depth + wallet | Exchange limits | ~850 shares / market | Points / creator rules | Gas + illiquidity |
| Settlement | Oracle challenge window | Ops hours–days | Centralized ops | Creator / mods | REP reporting rounds |
| Dispute | Optimistic oracle | Exchange rulebook | Platform determination | Community / admin | Bonds + invalid |
| Sweet spot | Global elections, culture | US macro, marquee politics | US politics signal | Practice, niche questions | Permissionless long-tail |
No row wins every column. The matrix is an input to choice, not a scoreboard for fandom.
Fees: what hits expected value
Polymarket charges trading fees plus chain costs; the hidden tax is slippage on pool legs. Kalshi lists per-contract fees; the hidden tax is spread at the touch. PredictIt often charges a percentage of profits, not only notional fees—great for small exploratory wins, painful for high-conviction wins at the cap. Manifold mana is usually cheap; real-money lanes need their own row in your spreadsheet. Augur taxes events: mint, trade, redeem, dispute opportunity.
Imagine the same 60¢ YES entry with $500 notional that wins. Kalshi might net near $190 after illustrative taker fees; Polymarket near $185 after fees, slippage, and gas; PredictIt nearer $165 after a wider ask and profit tax; mana $200 in play money that is not dollars; Augur near $187 after gas—exact numbers vary, but the shape of frictions differs by venue family.
Profit-fee venues shift EV math toward win-branch haircut; taker-fee venues shift it toward every fill; gas venues shift it toward ticket count. Your spreadsheet should mirror the venue family, not a single generic “2% fee.”
Limits and Kelly ceilings
PredictIt’s 850-share cap binds before Kelly on most bankrolls—use it as signal, not scale. Kalshi position limits may block arb size on marquee series. Polymarket large orders are the market on thin pools. Manifold mana supply is unlimited in fun, irrelevant for $50k thesis. Augur binds on gas and bonds, not share count alone.
An 8¢ edge on a $10,000 bankroll might deploy $3k–$8k on liquid Kalshi, $1k–$15k on Polymarket depending on simulator output, $500–$850 on PredictIt, 100% mana only in the gym, and $500–$2k on Augur before costs dominate. Kelly recommends a fraction; venue limits recommend a ceiling—take the minimum.
Three clocks: discovery, deposit, redeem
Price discovery is fastest on liquid Kalshi and Polymarket books; PredictIt can lag minutes on news; mana is instant; Augur moves at block pace. Deposits range from ACH days on Kalshi to wallet minutes on crypto. Post-event redeem ranges from fast USD credit on centralized venues to challenge windows on Polymarket and reporting rounds on Augur.
News trading gaps across apps are not free arb if resolution sources differ. A Polymarket jump in seconds plus a PredictIt stale quote is information lag, not profit, until rules and size align.
Regulation as a payoff state
Kalshi risk is rule change and delisting. Polymarket risk is enforcement and geo blocks. PredictIt risk is no-action terms and platform continuity. Manifold real-money risk is terms changes. Augur risk is local law plus protocol governance. Model cannot trade or cannot withdraw alongside event NO when you build scenario trees for bankroll survival.
Structural arb feasibility
Kalshi and Polymarket sometimes align when rules byte-match and both sides can move size—KYC, USDC, and timing still bite. Kalshi and PredictIt are usually signal pairs because caps and profit fees block scale. Polymarket and Augur rarely arb because oracle families differ. Manifold versus any USD venue is not arb—currencies differ. Headline equality is insufficient; run rules diff before you chase cents.
When gap exceeds four cents after fees, assume arb capital is already moving unless you have a rules appendix that proves isomorphism.
Product-type routing
Binary macro and rates favor Kalshi and Polymarket with clear official feeds. Categorical nominee slates need sibling consistency checks on both. Scalar CPI-style thresholds often live on Kalshi with index definitions in the PDF. Culture props favor Polymarket listing speed or Manifold probes. Conditionals and bundles must be venue-native—do not cross-mint combos across engines.
The “cheaper side” trap
Kalshi YES 52¢ versus Polymarket display 48% tempts a story. Stop if resolution sources differ—AP call versus another feed is correlated bet, not arb. Run Polymarket simulator on $2k; effective price might be 54¢, more expensive than Kalshi. PredictIt at 55¢ ask with 850 cap is signal only. Matrix thinking starts with rules parity, then all-in executable price, then limits.
Goal-based ranking
Serious USD politics and macro → Kalshi first, Polymarket if you have access and depth. Crypto-native narratives → Polymarket. Academic price discovery and teaching → PredictIt plus Manifold watchlists. Forecast training → Manifold mana, then graduate. Permissionless experiments → Augur with invalid priced in.
Liquidity language without a second table
On Polymarket, ask whether the tile is pool or book before you call depth “good.” On Kalshi, read cents of spread and shares at touch. On PredictIt, assume wide unless proven otherwise. On Manifold mana, ask who subsidized the curve. On Augur, estimate gas-adjusted size and time to redeem. The matrix column “engine” tells you which question to ask; it does not answer it for you.
Scoring your goal in prose
If your goal is serious USD politics, rank Kalshi first and Polymarket second when onboarded. If your goal is crypto narrative speed, rank Polymarket first. If your goal is teaching or homework, rank Manifold mana and PredictIt signal. If your goal is uncensorable listing, rank Augur with invalid priced in. If your goal is cross-venue arb, require rules lawyer mindset—most headlines fail the test.
Worked comparison without a spreadsheet grid
You want $3,000 on a Fed binary. Kalshi shows 2¢ spread and depth at the ask; Polymarket shows 48% on the pool but simulates 51¢ for your ticket; PredictIt shows 54¢ ask and caps you at $500 notional; Manifold mana shows 47% but is not USD; Augur quotes 49¢ with $12 round-trip gas. The “cheapest” headline is Kalshi or Polymarket depending on simulator output—not PredictIt, not mana, not Augur at this size. That narrative is the matrix in action.
Key ideas
Use one table for columns, prose for rows you care about. Refresh numbers quarterly. Rules parity before price parity. Limits before Kelly. Clocks before hold discipline.
How the matrix feeds Module 07
Strategies assume a venue row is already chosen: passive hold, momentum, arb execution, and hedging all need the friction row you picked here. Journaling should record matrix columns that mattered—fee type, cap, clock—not only entry price.
Next: How to Choose a Platform Based on Your Goals