秋田预测市场 · Discord 审计

Taker fees计算错误及rebates未支付

2026-06-25 · Polymarket · 46 条相关讨论

satatardy 2026-06-25 05:31:01

Just letting fellow devs know that taker fees are broken and as a result: 1) Taker fees are often higher (and never lower) than what you'd expect from looking at fills and using the formula from the docs 2) Taker fees and maker rebates from the same trades don't always line up as they should 3) You can be charged different fees for the exact same taker trades, depending on what orders were sent to make those trades 4) Buying shares in a winning outcome can actually cause you to lose money Number 4 is the most alarming imo since making winning trades should never cause you to lose money, but number 3 is the most actionable since you can save money on taker fees by sending different orders, even while making the exact same trades. This was reported on Cantina but polymarket decided to be lazy as usual and ignore it. I've attached the full report

Just letting fellow devs know that taker fees are broken and as a result: 1) Taker fees are often higher (and never lower) than what you'd expect from looking at fills and using the formula from the docs 2) Taker fees and maker rebates from the same trades don't always line up as they should 3) You can be charged different fees for the exact same taker trades, depending on what orders were sent to make those trades 4) Buying shares in a winning outcome can actually cause you to lose money Number 4 is the most alarming imo since making winning trades should never cause you to lose money, but number 3 is the most actionable since you can save money on taker fees by sending different orders, even while making the exact same trades. This was reported on Cantina but polymarket decided to be lazy as usual and ignore it. I've attached the full report

TheQuestToBeSharpe 2026-06-25 05:33:32

Fwiw my local calculations go via what I think the documentation implies, and I sometimes seem to get lower fees charged than expected

Fwiw my local calculations go via what I think the documentation implies, and I sometimes seem to get lower fees charged than expected

satatardy 2026-06-25 05:34:57

The higher fees only happen to taker orders that trade with maker orders at multiple different price levels. Do you have an example of getting lower fees than you expected? I've never seen that

The higher fees only happen to taker orders that trade with maker orders at multiple different price levels. Do you have an example of getting lower fees than you expected? I've never seen that

satatardy 2026-06-25 05:43:26

They do just use average price, that's the problem. The correct way would be to do it per level

They do just use average price, that's the problem. The correct way would be to do it per level

satatardy 2026-06-25 05:44:08

They are, you can check

They are, you can check

satatardy 2026-06-25 05:47:52

It's pretty easy to check, just make a taker order that trades with maker orders at multiple different price levels, preferably quite far apart so the difference is obvious. Then calculate the fees using the average price for the whole trade or by calculating them per level. Then check the USDC amount transferred onchain and you'll see it matches the first method

It's pretty easy to check, just make a taker order that trades with maker orders at multiple different price levels, preferably quite far apart so the difference is obvious. Then calculate the fees using the average price for the whole trade or by calculating them per level. Then check the USDC amount transferred onchain and you'll see it matches the first method

satatardy 2026-06-25 05:49:53

Someone from polymarket actually gave a response on Cantina basically acknowledging that this is how it works but tried to claim there's nothing wrong with it. That finding was disputed and then they just ignored it

Someone from polymarket actually gave a response on Cantina basically acknowledging that this is how it works but tried to claim there's nothing wrong with it. That finding was disputed and then they just ignored it

satatardy 2026-06-25 05:51:40

That's different, the inconsistency here is caused by them using different formulas for taker fees and maker rebates

That's different, the inconsistency here is caused by them using different formulas for taker fees and maker rebates

satatardy 2026-06-25 05:51:59

Because the taker fees are calculated on the average price but the maker fees are calculated per level

Because the taker fees are calculated on the average price but the maker fees are calculated per level

satatardy 2026-06-25 05:53:48

They genuinely just seem lazy and short-sighted idk what else to say

They genuinely just seem lazy and short-sighted idk what else to say

satatardy 2026-06-25 05:55:06

But yeah aside from polymarket's incompetence I posted here because you can actually save on taker fees by sending your orders differently, even when they result in the exact same trades, so I suggest anyone here who pays significant taker fees should read it

But yeah aside from polymarket's incompetence I posted here because you can actually save on taker fees by sending your orders differently, even when they result in the exact same trades, so I suggest anyone here who pays significant taker fees should read it

Vader 2026-06-25 05:56:39

This sounds so much like a typical PM thing to do.

This sounds so much like a typical PM thing to do.

Chien mechant 2026-06-25 06:48:32

They had huge funding since the start they could have hired some competent devs

They had huge funding since the start they could have hired some competent devs

SharkHunter 2026-06-25 06:48:59

Hey - Asking again here how rebates work, its not 30-50% of fees refunded, how is it actually measured?

Hey - Asking again here how rebates work, its not 30-50% of fees refunded, how is it actually measured?

SharkHunter 2026-06-25 07:08:33

Ups n downs 🙂 but nobody seem to figure out how these rebates are measured

Ups n downs 🙂 but nobody seem to figure out how these rebates are measured

Kosmolojec (❖,❖) 2026-06-25 08:20:40

"Update: Taker rebates level up bonuses will be paid starting from Monday June 29th onwards, on the day new levels are reached." - does it mean that we will not get rewards for already reached levels?

"Update: Taker rebates level up bonuses will be paid starting from Monday June 29th onwards, on the day new levels are reached." - does it mean that we will not get rewards for already reached levels?

xDay 2026-06-25 15:02:14

still no taker rebate?

still no taker rebate?

SlickCodeStu 2026-06-25 15:36:51

Anyone got their level up bonuses yet?

Anyone got their level up bonuses yet?

torchoverflow 2026-06-25 15:47:24

I did not receive any taker rebate. Only get the level, what is wrong

I did not receive any taker rebate. Only get the level, what is wrong

torchoverflow 2026-06-25 15:50:45

I have the volume, have the level, but no taker rebate, no level up rebate

I have the volume, have the level, but no taker rebate, no level up rebate