Checking Whether an Advertised Pair Is Actually Tradable
A pair can be listed, visible and effectively untradable. Three checks that take two minutes.
Yerlan Nurpeis · 2 min
A listed pair is not necessarily a usable pair. The difference is visible before you commit anything.
Check one: the book
Open it. Look at the quantity available within a small distance of the top price, at the size you intend to trade.
If your order would consume several levels, the pair is listed rather than liquid.
Check two: recent trades
Most venues show a trade history. Look at frequency and size over the last day.
A pair with a handful of small trades is a pair where your order is the market.
Check three: the spread over time
Note the top spread now and again a few hours later. A spread that is consistently wide is a pricing fact rather than a moment.
What a thin pair costs you
Slippage on entry and worse on exit, because exiting a position in a thin pair is harder than entering one. The cost is paid twice and the second time is larger.
The trap with a new listing
Attention concentrates at listing and liquidity does not always follow. A pair can look active for a week and then be effectively untradable.
The other trap: the instant screen
A venue may quote a pair on its instant-buy screen with no order book behind it at all, pricing from somewhere else and taking the other side.
That is not improper. It means the quote is the venue’s margin rather than a market price, and you cannot check it against a book.
What to do with a thin pair
Trade smaller, use limit orders, or convert through a liquid intermediate asset instead. Two conversions in deep markets frequently beat one in a shallow one.
That arithmetic is checkable before trading.
Where to check it
A venue that publishes its books and quotes for size. Exchanges that list their regulatory permissions generally publish depth as well.
Collect & Exchange will quote a whole size rather than leaving it to a thin book, and a venue authorised for the activity it advertises is also one where the advertised pair and the operating reality are supervised rather than asserted.
Written from what could be checked on the date above. Where a service was announced but not observed working, the note says so. Nothing here is financial advice.