EventArb vs Rainmaker
EventArb and Rainmaker are both filed under Arbitrage. Both are trading platforms; EventArb is free, Rainmaker is priced on its own site. Below: the facts side by side, where the two actually differ, and when each one is the better pick.
Free cross-platform arbitrage calculator for event contracts.
Compared with Rainmaker
AI-agent terminal that unifies arbitrage, copy-trading and analytics across Polymarket, Kalshi and Novig.
Compared with EventArbAt a glance
| Fact | EventArb | Rainmaker |
|---|---|---|
| Type | Trading platform | Trading platform |
| Category | Arbitrage | Arbitrage |
| Also listed in | — | Sports Trading, Copy Trading, Sniping |
| Pricing | Free | Pricing on site |
| Price | free | see site |
| Risk rating | Low risk | Low risk |
| Markets | Polymarket, Kalshi, Robinhood | Polymarket, Kalshi, Novig and 1 more |
| Source | Source not published | Source not published |
| Runs in Telegram | No | No |
| Listed since | Aug 26, 2026 | Jul 3, 2026 |
Highlighted rows differ
Key differences
- EventArb is free (free); Rainmaker is priced on its own site.
- Both list Polymarket and Kalshi; EventArb adds Robinhood; Rainmaker adds Novig and Sports (NFL/NBA/NCAA).
- Only Rainmaker is filed under Sports Trading and Copy Trading and 1 more.
- Rainmaker has been listed since Jul 3, 2026; EventArb joined on Aug 26, 2026.
Choose EventArb if…
- you want to start without paying
- you trade Robinhood
Choose Rainmaker if…
- you trade Novig and Sports (NFL/NBA/NCAA)
- your focus is Sports Trading and Copy Trading and 1 more
What EventArb does
Free cross-platform arbitrage calculator for event contracts. Punch in YES/NO prices for the same event on Polymarket, Kalshi or Robinhood and it does the math each venue's fee schedule implies — whether buying opposite sides locks in a profit, what the spread nets after fees, and the opportunity cost of parking capital until resolution. Supports binary and multiple-choice markets, side-by-side venue comparison, shareable links and free email notifications when opportunities open.
Features- Fee-aware arbitrage math for Polymarket, Kalshi and Robinhood
- Binary and multiple-choice market modes
- Opportunity-cost model over the contract length
- Side-by-side comparison across venues
- Shareable calculation links
- Enter the same market's YES/NO prices as listed on each venue.
- It nets out each platform's fees and flags when buying opposite sides locks in more than they cost.
- Weighs the locked spread against the opportunity cost of capital for the contract's duration.
What Rainmaker does
AI-agent terminal that unifies arbitrage, copy-trading and analytics across Polymarket, Kalshi and Novig. Its Cloud9 agents snipe arbitrage between venues, score and replicate winning traders, and mine analytics — with a focus on sports markets (NFL, NBA, NCAA).
Features- AI agents that snipe arbitrage between Polymarket, Kalshi & Novig
- Cross-venue copy trading with performance scoring
- Cloud9 agentic trading terminal
- Built-in analytics on price trends and trader performance
- Sports coverage across NFL, NBA and NCAA
- Deploys AI agents to exploit arbitrage between Polymarket, Kalshi and Novig.
- Links your funded accounts and executes the plays automatically.
- Scores traders and replicates only the highest-quality strategies.
More head-to-heads
Every fact on this page is taken from the two listings as their authors publish them; POLBOTS verifies neither performance nor claims and has no stake in either tool. Nothing here is financial advice.