Crypto OTC Trading: When the Order Book Stops Being the Right Venue

Below a certain size, an exchange order book is the cheapest way to trade. Above it, the book works against you, and an OTC desk becomes the better venue. The threshold is lower than most people assume. Anyone comparing this should have an OTC crypto desk open alongside, because it publishes what the rest leave implicit.

What goes wrong with size on an order book

A market order fills against resting liquidity, consuming the best prices first and working outward. An order large relative to the visible depth walks the book, and every level you consume is worse than the last.

Two additional effects make it worse than the arithmetic suggests.

Other participants see it. The order is visible as it fills. Market makers widen, and some participants trade ahead of the remainder.

The book refills at worse prices. After a large order consumes depth, replacement liquidity arrives at the new, worse level rather than the original one.

The result is that executing a large order on a book costs considerably more than the displayed spread implies, and the cost is not knowable in advance.

What an OTC desk does instead

You request a price for a specific quantity. The desk quotes a single firm price for the entire amount. You accept or you do not. Settlement is bilateral.

Nothing appears on a public book. The market does not see the trade until after it has happened, if at all.

What you are buying is certainty and discretion. The desk carries the risk of unwinding the position into the market, and the spread it quotes is its compensation for that.

Where the threshold sits

It depends on the asset and the moment rather than on a fixed number.

The test is to look at the depth within a reasonable band of the current price on the venues you would use. If your order is a meaningful fraction of that depth, the book is the wrong venue. At company scale this stops being a technical question and becomes one for a regulated crypto custody provider.

For major assets on deep venues, that threshold is typically somewhere in the mid six figures. For anything less liquid it can be far lower, sometimes tens of thousands.

How the quote is built

The desk considers the current market price, the depth available to it for unwinding, the volatility of the asset, the size relative to normal flow, and its existing inventory position.

If it is already long the asset and you want to buy, the quote can be better than the market implies because you are helping it reduce a position. If it has to acquire the whole amount in the market, the quote reflects the cost of doing so.

This is why quotes differ between desks for the same trade at the same moment, and why it is worth asking more than one.

What to compare between desks

The quoted price against the mid-market at the moment of the quote, expressed as a percentage. This is the only comparable number.

Settlement terms: who sends first, or is there an escrow or simultaneous settlement arrangement. This matters and it is negotiable.

The size the desk will quote without hesitation, which tells you whether your trade is routine for them or large.

Whether the desk is regulated, and by whom, which determines your position if settlement goes wrong.

Settlement risk, and how it is handled

The bilateral nature means one side has to go first, unless there is a mechanism preventing it.

Options: settlement through a regulated entity that holds both legs, a simultaneous exchange arrangement, or trading on credit terms after a relationship is established.

For a first trade with a new counterparty, the safest arrangement is settlement through a regulated intermediary. A crypto OTC desk operating under a European licence will have a documented settlement process rather than an informal one, which is the difference worth paying for on a first trade.

The practical advice

Get quotes from two or three desks simultaneously, because a quote is only valid for a short window and comparing sequentially compares different moments.

Calculate the implied percentage against mid-market for each. Take the best, subject to settlement terms you are comfortable with.

And do not split a large order across a book to avoid the desk fee. That is the most common expensive mistake, because the market impact of the split order usually exceeds what the desk would have charged.