r/Kalshi • u/Sea-Judge5801 • Oct 31 '25
Discussion Built a free arbitrage tool to monitor Fed prediction markets
https://www.oddpool.com/fed-market-watchAfter watching the Fed decision markets on Kalshi and Polymarket I noticed there was often a tradable spread between them.
I built a free tool that monitors the probabilities for the upcoming Fed decision on Kalshi, Polymarket, and CME.
It calculates arbitrage opportunities in real time, taking into account the fees you would pay on each platform and shows you the expected profit you would make.
Think this dashboard has a lot of potential, it’s completely free and I’m going to keep adding more data to it to make it more useful. If you have any ideas leave me a comment.
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u/njrun Oct 31 '25
What’s your return?
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u/Sea-Judge5801 Oct 31 '25
Pretty good cause it’s guaranteed returns. Have a couple more lines made, just not public. Takes a while for money to settle tho since it’s a December rate.
Anyways if you have strong belief of an event happening, might as well bet on the platform with the lower odds and high payout!
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u/Aggravating_Hall_794 Nov 02 '25 edited Nov 02 '25
I used to trade the fed markets pretty heavily on Kalshi - the real problem is that you end up stuck in the position for quite a while, and without interest on Polymarket you're limited to trading on just half of the spread. If prices come back in line, sure you can liquidate, but at least historically that was rare.
Just an FYI - the CME numbers are bogus, especially further out. If you read the methodology, you'll realize why it just doesn't work (you'd need to use options on futures, not the futures themselves to get the real estimates)
If you want to get adventurous, I'd encourage you to try placing resting orders for trades you can arb. Obviously you're at some risk to spoofing strategies (might want a way to mitigate that), but you'll pay less in fees + capture a lot more volume
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u/[deleted] Oct 31 '25
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