The pool holds brokers and ETH at the same time. Price is not read off an
exchange — it is set by a curve. Every broker taken out of the pool lifts the
price by 0.55%; every one sold back drops it by the same.
buy n: cost = spot × d × (dⁿ − 1) / (d − 1)
sell n: gain = spot × (1 − d⁻ⁿ) / (1 − 1/d)
d = 1.0055
Two fees, both paid by whoever initiates the trade, in both directions:
- 2.0% pool fee
- 2.5% collection royalty
Because buying and selling cost the same, the desk has no opinion on where price
goes. If the pool runs low the curve prevents a cliff — the fewer brokers left,
the more the next one costs. At zero, buying pauses until someone sells back, and
the ETH stays in the pool and available to sellers the whole time.