Trading the order book
The one order type, what a resting order locks, how the book decides who fills first, how a merged ladder reads, and what your open orders do when the market resolves.
An order-book market takes exactly one instruction: a limit order. You name a side, a price and a number of shares, and the book either finds someone on the other side of it or holds your order until someone arrives. Every other control on the trade panel is built out of that one primitive.
Read this first
Acepyr is pre-mainnet. The $ACEPYR that exists today is a testnet token, a symbolic point system. It carries no economic value, no USDC claim, and no revenue share. It cannot be bought and may never have any value. For anything money-related, How Acepyr's economics work is the single source of truth.
This page is the operating detail. For what an order-book market is, and how it differs from a curve market, start with the Overview.
What you can ask for
| Field | What's allowed |
|---|---|
| Side | Buy or sell |
| Outcome | The YES side or the NO side. Each is its own order |
| Price | A whole cent from $0.01 to $0.99. Never $0.00, never $1.00 |
| Size | A whole number of shares, minimum 1 |
| Lifetime | Rest until you cancel (the default), rest until a time you choose, or fill now and cancel whatever doesn't |
Two things follow from the price rule. Prices move on one-cent ticks, so nobody can jump the queue by a hundredth of a cent: to get in front of a resting order you have to beat it by a full cent, and pay for it. And because both ends are excluded, a market can be priced at near-certainty without ever quoting the certainty itself.
A fill-now order cannot also carry an expiry time. An order that never rests has no resting deadline, so asking for both is refused rather than silently resolved one way.
How long an order rests
An expiry is picked from a menu scaled to the market's length. Durations longer than the time the market has left are dropped, and a long market nearing its close moves to a shorter menu.
| Market length | Expiry choices |
|---|---|
| Up to an hour | 1, 5, 15 or 30 minutes |
| Up to six hours | 5, 15 or 30 minutes, or 1, 2 or 4 hours |
| Longer | 1, 4, 12 or 24 hours |
When the time passes, the order is cancelled and whatever it locked is released.
The "market buy" button is a limit order
There is no separate market order. The buy button prices your order through the book and attaches a slippage cap, which makes it a limit order with the limit chosen for you. You can never fill worse than that limit. A worse fill is structurally impossible, not merely unlikely.
What your order locks
A buy locks $ACEPYR
Your price times your shares, plus 5% on top to cover the fee if your order crosses. That margin is not a charge. Whatever the fee does not consume is released back to you as the order fills.
A sell reserves shares
Selling reserves the shares out of your position. No $ACEPYR moves and nothing is deducted: the shares are simply unavailable to be sold a second time while the order is open.
Cancelling releases it immediately
Cancel an open order at any time and the lock comes straight back. An expiry, if you set one, releases it the same way when the time passes.
You cannot quote a price you cannot back. That is what makes a resting order in the book a real, costly position rather than an indication of interest.
Who fills first
The book fills in a strict order, and both steps matter if you rest orders regularly.
| Rule | What it means for you |
|---|---|
| Best price first | The book looks for the best price available to you, not the first order it happens to find. Someone crossing the spread reaches the best resting price, not the earliest one. |
| Then oldest first | Among orders at the same price, the one that has rested longest fills first. Queue position is earned by arriving early, and it is lost the moment you re-price. |
| Your own orders are skipped | If your incoming order would cross an order you already have resting, that order is passed over and yours rests alongside it. You are never refused for it, and you never trade with yourself. |
Partial fills are normal. An order that meets a smaller counterparty fills for what is there and stays open for the remainder, at the same price, keeping its place in the queue.
There is no amend. Changing the price or size of a resting order means cancelling it and placing a new one, which starts you at the back of the queue at the new price.
Reading a book that shows both sides at once
The ladder shows one price scale, but four kinds of order feed it. A NO order is folded into the YES frame at the complementary price:
| A resting order | Appears on the ladder as |
|---|---|
| Buy NO at $0.45 | A YES ask at $0.55 |
| Sell NO at $0.45 | A YES bid at $0.55 |
This is why a book with nothing but buyers still shows a spread rather than an empty ask column. Two people bidding $0.49 for YES and $0.49 for NO produce a ladder reading $0.49 bid, $0.51 ask: a two-cent spread built entirely out of buy orders.
Sharing a ladder line is not the same as trading with each other
A sell of NO and a buy of YES can sit at the same displayed price and still not match. A NO share is neither a YES share nor the cash to pay for one. The ladder merges them so the price reads correctly; the book still matches them as the separate instruments they are.
What it costs
The side that crosses the spread pays the fee. The side that was resting does not.
The fee is not a flat percentage. It is at its largest on a market trading near even money and falls away toward both ends, so crossing an uncertain market costs the most and crossing a nearly-settled one costs very little:
| Price you fill at | What the crossing side pays |
|---|---|
| $0.50 | 0.80% of the fill |
| $0.25 or $0.75 | 0.60% |
| $0.10 or $0.90 | 0.29% |
| $0.05 or $0.95 | 0.15% |
| $0.01 or $0.99 | 0.03% |
There is no second fee at settlement. A winning share credits the full $1.00. What you paid when you traded is the whole of it.
The resting side is credited a rebate rather than charged. Market making covers that side.
This schedule can change
The rates above are the schedule in force now, not a commitment. They are set deliberately and can be moved. Check this page rather than a number you wrote down.
What happens to your open orders when the market resolves
Nothing is stranded.
Resolution empties the book
The moment a market resolves, every open order on it is cancelled and every buy's escrow is released.
A sweep catches anything the first pass missed
A background job runs on a one-minute cycle and cancels open orders on any market that is no longer trading. If the immediate pass fails for any reason, this one collects it within the cycle.
Positions settle separately
Cancelling orders never touches what the market owes the people holding shares. Shares on the winning side pay $1.00 each and shares on the losing side pay $0.00, out of the reserve traders themselves paid in.
Because every share on the book was created backed by a full dollar, the reserve holds exactly $1.00 for every outstanding pair. That is why a winning book share redeems for the whole dollar rather than a scaled portion of whatever is left.
FAQ
Related
- Overview — what an order-book market is, and how it differs from a curve market
- Market making — the resting side, the rebate, and where the spread comes from
- The market maker's playbook — how to place orders that rest, quote both sides, and manage one-sided fills
Questions
Email auriza@acepyr.com.