A spreadsheet is a good way to learn the arithmetic of prediction market arbitrage and to keep a record of your trades. It does not find opportunities for you. Here is an honest comparison with Arbitrage Agent's Starter plan, which is a live signal feed with step-by-step guides.
| Feature | Arbitrage Agent | Spreadsheet Tracking |
|---|---|---|
| Finding opportunities | Scans matched Kalshi and Polymarket markets continuously and lists the ones that clear fees | You look up prices on both platforms yourself and type them in |
| Market coverage | Every pair in the matched catalogue | Whatever you choose to track |
| Placing orders | You place both legs yourself, following a step-by-step guide (Starter). Automated execution is planned for Operator, which is coming soon | You place both legs yourself |
| Alerts | Not in Starter (Telegram/email alerts are planned for Operator, coming soon) | None, unless you build them |
| Fee maths | Computed per signal from the fee rules we implement | Your own formulas, which you must keep up to date |
| Matching two markets as the same event | AI matching plus a check of the resolution rules, so some pairs are rejected | You read both rulebooks yourself |
| Recording what you traded | Trade history and P&L in the dashboard | Whatever columns you design; fully flexible |
| Cost | Starter from $29/month | Free, plus your time |
Some traders track prediction market arbitrage in Google Sheets or Excel: they note the YES and NO prices on both platforms, compute the net edge with formulas, and log each trade to follow their results.
A spreadsheet is a very good way to learn the mechanics. Building your own edge calculator forces you to understand fees, the difference between price and cost per contract, and position sizing in a way that using a ready-made tool does not. It is also the most flexible way to record your own trades.
What a spreadsheet does not do is find opportunities. Prices have to be typed or pasted in from two platforms, so by the time an edge shows up in a cell it may already be gone. Net edges on these markets are often below 1%, so a stale price or an out-of-date fee formula can turn a profit into a loss.
Arbitrage Agent monitors thousands of binary event markets across Polymarket and Kalshi continuously. AI-powered semantic matching — every pair validated before it goes live — links identical events across platforms — even when titles differ completely.
When a price gap creates an arbitrage opportunity, the opportunity appears in your live feed with both legs ready to place. Automated parallel execution (with a circuit breaker that auto-unwinds if one leg fails) is in final testing and rolls out to Operator subscribers first. The agent is fully non-custodial — your capital stays on Kalshi and Polymarket at all times.
Difference 1
Arbitrage needs two markets that resolve on the same event, priced so that YES on one plus NO on the other costs less than $1 after fees. A spreadsheet can check that sum for the markets you have already entered. It cannot tell you which markets on Kalshi and Polymarket are the same event, and it cannot watch thousands of them. Arbitrage Agent maintains a matched catalogue and lists the pairs whose combined cost clears fees.
Difference 2
Fee schedules change and differ by platform. Kalshi's taker fee, for example, is calculated per order as 0.07 × contracts × price × (1 − price), rounded up to the next cent, and it can differ by series; check Kalshi's current fee schedule before relying on any number. A formula that was right last month can quietly give a wrong net edge today. Whatever tool you use, re-check the fee rules against the platforms' own pages.
Difference 3
Two markets that look identical can resolve differently because of the source, the deadline or the edge cases. A spreadsheet leaves that check entirely to you. Arbitrage Agent compares the resolution rules of both markets and rejects some pairs, but it does not remove the risk, and you should read both rulebooks before you trade.
Difference 4
On the Starter plan you still place both orders yourself, on each platform, with your own accounts and funds. The guides walk you through the steps. There is no automated trading in Starter, and prices can move between the moment a signal is shown and the moment you place an order.
When to choose Spreadsheet Tracking
When to choose Arbitrage Agent
Use a spreadsheet to learn and to keep your own records; it costs nothing and teaches the maths. Use Arbitrage Agent Starter if you want the finding and matching done for you and are happy to place the orders yourself. The two also work together: many people keep a sheet for their own trade log.
Can I use a spreadsheet to paper-trade arbitrage first?
Yes, and it is a sensible first step. Logging hypothetical trades shows you how the maths and the fees work before you put money at risk.
What formula do I need?
The core check is: cost of YES on one platform + cost of NO on the other + fees < $1.00. The gap is your gross edge per contract before any resolution risk. Kalshi's taker fee is documented as 0.07 × contracts × price × (1 − price), rounded up to the next cent; check each platform's current fee schedule for the exact rules. The free calculator at arbitrage-agent.com/calculator can help you check your numbers.
Does Arbitrage Agent Starter place trades for me?
No. Starter shows a live feed of signals and step-by-step guides; you place both orders yourself. Automated execution is planned for the Operator plan, which is coming soon.
See the live arbitrage feed
Both legs ready to place, with a step-by-step guide. You trade on your own accounts. No coding required.
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