You now have five venue portraits and a comparison matrix. This closing chapter turns that research into a decision: which platform matches your goal, jurisdiction, size, and time horizon—without tribal loyalty to an app icon. The strategies module ahead assumes you can execute a plan; this chapter ensures the plan rides the right rails.
Four gates before you deposit
First: Can you legally access, trade, and withdraw where you live? If not, stop—regulation is a payoff state, not a footnote. Second: Does the venue list the contract shape you need—binary, categorical, conditional, bundle—and is the series open? Third: Is resolution text objective enough for how long you will hold through disputes? Fourth: Does all-in expected value still clear your edge after fees, spread, slippage, profit taxes, and gas?
Fail any gate and no trade beats the wrong venue. Write the four answers in one sentence in your journal before you size—thirty seconds that prevents expensive venue mistakes.
Personas without tribalism
A US macro or elections trader with $1k–$50k should default to Kalshi for regulated USD depth and use Polymarket only with working access and simulator-confirmed liquidity; PredictIt is a watchlist, not a sizing home. A crypto-native trader who lives in headlines and wallet UX will center Polymarket and add Kalshi when USD rails matter. A student or forecaster in training should live on Manifold mana, peek at PredictIt spreads, and avoid Augur gas until basics are solid. An academic or policy researcher may read PredictIt and Kalshi for publishable prices while using Manifold for probes. An on-chain maximalist experimenting with uncensorable lists accepts Augur invalid risk. A cross-venue arb specialist needs Kalshi plus Polymarket with lawyer-grade rule matches—PredictIt caps block the weak leg.
Personas overlap; pick one primary venue for bankroll accounting and treat secondaries as signal, not duplicated risk. Two apps on your phone does not mean two independent bets on the same election narrative.
A simple decision flow
If legal access and USD statements matter, start with Kalshi when the contract exists and depth passes your simulator. If you need global listing speed and accept wallet plus oracle tails, Polymarket is the parallel path. If you need permissionless listing and priced invalid risk, Augur—with small size. If you are learning, Manifold mana first; if you need capped US politics signal, PredictIt alongside, not instead of, depth venues.
The flow is not “pick your favorite brand”; it is goal → legal → contract → EV → engine → dispute clock.
Size tiers
Under $500, Manifold and small PredictIt stakes are cheap tuition—learn resolution wording and spread math. $500–$5k conviction belongs on Kalshi marquee or Polymarket with simulator proof. $5k–$50k stays on venues where depth tables absorb you; caps and slippage dominate. Above $50k, institutional discipline on Kalshi is realistic; PredictIt is unusable for scale; Augur is usually illiquid. Platform cap is a hard ceiling on Kelly—PredictIt is not “conservative Kelly,” it is no scale.
Time horizon versus dispute clocks
Day trading news favors Kalshi CLOB and liquid Polymarket books. Multi-week holds tolerate either centralized venue if rules are clean. Holding through resolution on ambiguous culture props favors centralized fast finalize over long UMA or REP rounds. Post-media “clinch” trades should avoid venues where bond disputes freeze redeem for days.
Election night with $8k on Senate control: PredictIt is signal-only at the cap; Polymarket works if simulator shows ≤2¢ slip; Kalshi works if depth absorbs; Augur and Manifold are the wrong tools for that USD thesis.
Contract-type routing
Fed funds binaries → Kalshi first; read index source in the PDF. Nominee slates → Polymarket or Kalshi with sibling sum checks. Culture props → Polymarket with AMM awareness. Conditionals → Kalshi when the exchange lists the tree. Bundles → venue-native only. Play-money probes → Manifold; never merge mana P&L with USD journals.
Two traders, same headline
A US lawyer with $12k holding through certification should pass all four gates on Kalshi: legal access, listed binary, AP-style rules, positive EV after fees—Kalshi is the pick. An EU developer with $800 learning might practice on Manifold, place small real Polymarket if KYC works, and skip Kalshi USD friction. Same tweet, different optimal venue. Neither is “smarter”; constraints differ.
Multi-venue stacks (disciplined)
Allowed: one primary execution venue for most bankroll; PredictIt or Manifold as signal; hedges only when rules match byte-for-byte; arb only with checklist discipline from the arbitrage chapters. Forbidden: treating a mana win as proof you should size Kalshi the same way; cheapest mid across apps without all-in prices and rules diff.
Revisit venue choice quarterly—fee schedules, geo rules, and product menus change after enforcement and election cycles.
Quarterly revisit checklist
Fees change. Geo blocks change. PredictIt caps and letters change. Polymarket hybrid priority changes. Kalshi product menus expand. Once per quarter, re-run your persona row: still legal, still listed, still positive EV after frictions, still the right clock for your hold. Venue loyalty without revisit is how edge decays silently.
Journal fields worth one line each
For every trade log: venue, contract slug, resolution source one-liner, engine at fill (pool/book), all-in entry, planned hold through dispute? (Y/N). Module 07 strategies become auditable when those fields exist; without them, you cannot explain why Kalshi beat Polymarket on trade twelve.
Mistakes that survive six modules
Cheapest mid across apps. Ignoring PredictIt profit fee. Pool percentage as Kalshi mid. Headline arb without oracle parity. Full Kelly on capped markets. Tribe over fit. Trading where you cannot withdraw. Sizing before reading resolution.
What you carry into strategies
Informative prices need depth and clear resolution. Engines differ under logos. Gaps are economics, not gifts. EV and Kelly need real fees. Product shape and settlement grammar must exist on the venue you pick. Platform choice multiplies or destroys edge gathered elsewhere.
Document venue, rule screenshot, and why in a journal entry per trade. Module 06 ends here; Module 07 begins tactics on the rails you selected.
Key ideas
Choose goal → legal → contract → EV → engine → dispute. One primary execution venue. Secondaries for signal only. Revisit quarterly. Document why in one journal line so future-you trusts past-you.
After you pick: one sentence of accountability
Before you click buy, finish this sentence: “I am trading {venue} because {goal} requires {engine/clock} and I accept {fee/cap/oracle tail}.” If you cannot fill the braces, you are not ready—regardless of how strong your forecast feels.
Students versus professionals (same gates)
Students may weight Manifold and PredictIt higher because tuition is cheap; professionals weight Kalshi and Polymarket higher because caps and clocks matter at size. The four gates do not change—only the default row in your mental matrix does. Re-run gates when you graduate from practice to size; venue loyalty from college is a common leak.
Module 06 map (closure)
Polymarket — hybrid global crypto liquidity and oracle tails. Kalshi — regulated USD order book. PredictIt — capped US politics signal. Manifold — mana gym, cautious real money. Augur — permissionless oracle risk. Matrix — frictions side by side. This chapter — gates and personas → pick once per trade.
Next: Passive Strategy: Buy-and-Hold to Expiry