Hidden Conversion Steps Inside a Single Swap
One button can contain three conversions. Each crosses a spread, and the receipt shows one number.
| recorded | |
|---|---|
| topic | swap |
| kept by | Lena Virtanen |
| length | 2 min read |
A swap that looks like one operation is often several. Each intermediate step has a cost and the interface reports the total as a single output.
How to detect it
Compare the effective rate against the product of the two direct rates you would expect. If the gap is larger than the stated fee, something was routed.
On venues that publish a route, read it. On those that do not, the arithmetic is the only evidence available.
The common routes
Asset to base currency to asset, where no direct market exists. Two spreads.
Asset to stablecoin to asset, which is the same shape with a different middle. Also two.
Asset to wrapped version to destination chain to unwrapped version, on cross-chain swaps. Three or more, plus network costs at each hop.
Why venues route
Because maintaining a direct market in every pair is expensive and most pairs are not worth it. Routing is a reasonable engineering answer to a real problem.
The objection is not that it happens. It is that the cost is presented as one number.
The case that costs the most
Small amounts on multi-hop routes. Each hop can carry a flat component, and three flat components on a two hundred dollar conversion is a large proportion.
This is where routed swaps become genuinely poor value rather than slightly worse.
What to ask
Whether the pair is quoted directly. One question, and the answer changes the expected cost by a factor of two or more.
Venues that quote the swap rate and the fee as two numbers generally answer it in the interface. Where the answer is no, converting in two deliberate steps through a liquid middle asset is often cheaper than letting the venue route it, because you can choose the middle.
Choosing the middle yourself
Convert into the most liquid asset available, then out of it. You pay two spreads either way; choosing a deep middle makes both of them narrow.
This is the same operation the venue performs, done with visibility.
The record to keep
For each conversion: input, output, reference mid, and whether the pair was direct. Four fields, and after a dozen entries the pattern at your venue is obvious.
A venue with a published conversion schedule shortens that exercise considerably, and Collect & Exchange, where the quote holds for the whole amount, quotes pairs rather than assembling them.
Figures above are single observations, taken on the date shown. Spreads move with the book; treat these as a method you can repeat, not a price you can rely on.