Every number on the board, and what it means
The board shows what the venue reports, unmodelled. Knowing which two numbers to compare turns it from a wall of figures into a picture of how a market behaves.
What Arcus is- Type
- Perpetuals on stocks, gold, crypto and indices, one book
- Markets
- 60+ listed, read live from the venue
- Hours
- 24/7, including when the underlying share is closed
- Our data
- 4M+ order-book snapshots at a 5.5-second cadence
Volume against open interest: the ratio that says the most
Volume is how much changed hands in a day. Open interest is how much has not left. Neither means much alone, and their ratio means a great deal: it tells you whether the market is a place people trade through or a place people hold.
A book turning over more than twenty times a day is flow: positions open and close, and getting in and out is easy. A book turning over less than once a day holds patient money: harder to enter at size, and the other side of your view is held with conviction. On the board these two numbers sit next to each other for exactly this comparison.
- Volume ÷ open interest = how many times the market turned over today.
- Above about 20×: flow, easy to enter and leave.
- Below about 1×: patient positions, harder to move size.
Funding, and the trap of reading it as income
The board shows funding per hour and which side pays. Positive means the contract is above the reference price, longs are crowded, and longs pay shorts. It is a payment between traders, not a fee to the venue.
The trap is reading the live figure as what you will be paid. Most venues settle on an average across the interval, so a rate that spikes for ten minutes and returns has far less effect than the display suggests at the moment you look. What matters over a held position is the average, and whether the sign stayed put.
- Positive: longs pay shorts. Negative: shorts pay longs.
- The live number is a running estimate, not a settled amount.
- Persistence of the sign matters more than the peak size.
Margin, minimum order and the day range
Maintenance margin is the fraction of position value the venue requires you to keep. On the markets we measure it runs about 6.67 per cent on equities and crypto, 3.00 per cent on commodities and 2.00 per cent on indices, so the same dollar of position leaves you different amounts of room depending on what it is in.
The minimum order is five dollars of notional on every market, which is the practical reason a small account can hold a position in an expensive share. The day range bar shows where the current price sits between the 24-hour low and high: useful for seeing at a glance whether you are looking at a market that has already moved.
- Maintenance margin: ~6.67% equities and crypto, 3.00% commodities, 2.00% indices.
- Minimum order: $5 of notional, on every market.
- The range bar answers one question: has this already moved today?
What the board does not tell you
It shows what the venue reports and stops there. It does not show depth at your size: top-of-book and a day's volume are not the same as being able to fill a clip within a few ticks. It does not show how the venue behaves under load, which is the thing that decides whether you can exit during a violent move.
For those two you have to look at the book itself and watch one fast move before committing size. The board is a good filter and a poor substitute for that.
- Depth at your size is not on the board. Check the book.
- Behaviour under load is not on the board. Watch one fast move.
- Use it to shortlist markets, not to decide the trade.
Questions
What does open interest mean on a perpetual market?
The total value of positions still open. Volume tells you how much changed hands in a day; open interest tells you how much has not left. Comparing the two shows whether a market is traded through or held.
Why do two markets show the same funding rate?
Venues often clamp funding to a limited set of levels, so two markets sitting at the cap will display the same number. It is a mechanism artefact rather than a coincidence of positioning.
Is the data on the board delayed?
It comes from the venue's public API and is read straight through, with nothing modelled or estimated. Each page shows the time it was last updated.
Do I need an account to see the statistics?
No. The board and every individual market page are public; nothing is hidden behind a sign-in. An account is only needed to trade.