P × (1 − P) curve. So the rebate is largest
where quoting is hardest — around 0.50, where the outcome is genuinely
uncertain — and smallest at lopsided prices where a quote carries little risk.
Calibri’s rebate schedule mirrors Polymarket’s — the same fee curve, the same per-category rebate rates. If you already run a maker strategy there, the economics carry across unchanged.
What qualifies
You earn a rebate when your order was already resting on the book and someone else crossed into it. That is the only condition.
Each fill earns its own rebate. A large resting order that fills in five
pieces accrues five rebates, one per contract created.
How the rebate is calculated
The taker fee on a fill is:Because every maker’s rebate is proportional to the fee their own fills generated, this is the same distribution as a per-market pool split pro-rata by fee-equivalent — expressed directly, per fill, so you can compute what a quote earns before you place it.
Why the curve
P × (1 − P) is a bell curve: 0 at the edges, maximum 0.25 at 0.50, and
symmetric about the midpoint. Holding rate and size fixed, the rebate on a fill
relative to its maximum:
The practical read for a maker: quoting the uncertain middle of the book pays
several times what quoting the tails pays, for the same size filled. A fill at
0.30 and a fill at 0.70 pay identically — the curve is symmetric, so neither
side of the book is favoured.
Rebate rates by category
The rebate rate is the share of the taker fee paid to the maker. It is resolved from the market’s category; a category with no rate of its own falls back to 25%.
The last column is the maximum, at the top of the curve. Away from
0.50, scale
it by the curve: the same 100 contracts filled at 0.80 earn 0.16 / 0.25 =
64% of it.
Worked example
You rest a Crypto offer and it is filled for 100 contracts at0.60:
Rounding
- Rebates are denominated in USDC (6 decimals — one base unit is
0.000001 USDC). - The rebate is computed from the fee and rounded down to the base unit. A rebate below one base unit rounds to zero and never becomes a payable — this only bites on dust-sized fills at extreme prices.
When you get paid
1
Accrues at the fill
The moment your resting order fills, the rebate is recorded as pending.
No money moves for it at that point — only the taker’s fee moves.
2
Visible live
Pending rebates are readable in near-real-time, separated from referral
earnings:
3
Paid daily, to your Safe
A daily sweep pays pending rebates on-chain to your Safe — whether or
not the market has resolved. You do not wait for settlement to be paid for
quoting.
Voided markets
If a market is voided, every share pays 0.50 and the taker fee is refunded (see Voids and postponements). Rebates still pending for that market are removed along with the fee that funded them; rebates already paid are not clawed back.In short
Rest an order, get filled, earn a share of the taker’s fee — 15%, 20% or
25% depending on the category, on top of paying no fee yourself. The rebate
rides the same P × (1 − P) curve as the fee, so the uncertain middle of the
book pays most. Rebates accrue per fill and are paid daily to your Safe.
Related
Fees
The taker fee that funds every rebate, and the curve it follows.
Rewards
Payout mechanics shared by both reward programmes.
Referral program
The other way to earn a share of the taker fee.
Signed orders
Placing the resting orders that earn rebates.