fly · flight deck
Sheet 01 — the market, inflated
Thin air is cheap.
Every market charges the same fee whether it is climbing or collapsing. fly charges by air density instead — three percent at the floor, halving with every doubling above it, and never quite reaching zero, the same way the atmosphere never quite ends.
- Project
- fly
- Instrument
- Altitude-indexed fee
- Scale
- 8.5 km per e-fold
- Settles on
- Robinhood Chain · 4663
- Unit
- USDG
The same trade, two altitudes
300.00
USDG · at the floor
Thick air. The market is at its reserve, the contract is already bidding, and leaving costs the full 3.000%.
4.69
USDG · six doublings up
Thin air. The same 10,000 USDG trade, 64× above the floor, pays 0.047% — sixty-four times less.
Figures from the model on this page, not from a live market
Altitude
Height is a number the market already knows.
A token's floor is the USDG held in reserve behind each one in supply. Its altitude is how far the price sits above that floor — not in dollars, but in doublings.
fly converts that to metres at the atmospheric scale height, 8.5 km per e-fold, and reads the answer off an altimeter. Four times the floor is 11.8 km, a little above the tropopause, where a jet cruises.
There is no oracle in that sentence. The floor is a balance the contract holds; the price is what the pool quotes. Both are USDG, so altitude is measurable from inside the contract, block by block.
The whole protocol
One doubling is 5.89 km at every height — the curve has no special place on it. Altitude cannot go negative, because the floor is a live bid rather than a target.
Drag · the fee curve
The fee is the air you are flying through.
Drag on an aircraft scales with the density of the air around it. So does the fee here. At the floor the air is thick and leaving costs 3.00%. Every doubling above the floor halves it. Drag never reaches zero, and neither does the fee.
Works
Momentum stops paying a toll. Three doublings up the fee is 0.375% — a fifth of what a flat book takes — so the trade that pushes it higher is the cheapest trade on the venue.
Costs you
Leaving a weak market is expensive, on purpose. Near the floor you pay the full 3.00%, and you pay it to the people still holding. It falls hardest on the impatient.
Flight bands
Six altitudes, six fees.
Named for the layers they sit in, with the density and the fee the model returns at each. Nothing here is rounded to look tidy.
| Layer | Altitude | Price ÷ floor | ρ kg/m³ | Drag | Per 10,000 |
|---|---|---|---|---|---|
| Sea level | 0 km | 1.00× | 1.225 | 3.000% | 300.00 |
| Tropopause | 11 km | 3.65× | 0.3358 | 0.822% | 82.24 |
| Stratosphere | 20 km | 10.5× | 0.1165 | 0.285% | 28.53 |
| Upper stratosphere | 32 km | 43.2× | 0.0284 | 0.070% | 6.95 |
| Stratopause | 50 km | 359× | 0.00342 | 0.008% | 0.84 |
| Mesopause | 85 km | 22,026× | 0.0000556 | 0.0001% | 0.01 |
Ballast
The descent pays for the climb.
Drag is not revenue. Every unit of it is held as USDG ballast, and ballast has exactly one exit.
A balloon climbs by releasing ballast. Here the release is triggered by falling: when altitude drops back through a band it has already crossed, fly spends ballast as a bid under the market — the whole amount, in the band it just left.
The mechanism is self-loading. Selling near the floor is where drag is highest, so a sell-off fills the tank fastest exactly when the bid is needed most. Nothing is paid out to a treasury, and nothing leaves the aircraft.
Monotonic
Ballast only adds to reserve; retirement only subtracts from supply. The floor is their quotient, so it can only rise — no path through the contract lowers it.
Slow
A ratchet built from fees moves at the speed of volume. In a quiet market the floor barely moves for weeks, and nothing here changes that.
Why Robinhood Chain
A floor is only a floor if it is quoted in money.
Reserve, gas and quote are one unit. Altitude is a ratio of two balances the contract already holds.
Back a floor with ETH and the floor moves whenever ETH does. Holders wake up to a lower floor on a day nothing happened to the token. To read altitude you then need a price feed, and a price feed is a dependency, a latency and an attack surface.
Robinhood Chain is USDG-native. Ballast is dollars, the floor is a dollar number a holder can say out loud, and the pool already quotes in the reserve asset. No oracle, no second asset, no gas token to top up before you can exit.
Stated plainly: fly has no ticker and no deployed contract yet. Every figure on this page comes from the model described here, not from a live market. Nothing here is a quote, a price, or a promise of one.
Settlement
fly settles on Robinhood Chain.
A USDG-native Arbitrum Orbit rollup, chain id 4663, fully EVM equivalent. Gas is paid in the same unit the reserve is held in, so an exit never needs a second asset to go through.
- Drag, ballast and the floor are all denominated in USDG — one unit end to end, with no conversion step and no feed to trust.
- Altitude is derived from two balances inside the contract, so the fee for a block is computable by anyone reading state.
- Standard EVM execution with no custom opcodes, so any wallet or explorer that speaks Ethereum speaks fly.
Add the network
- Network
- Robinhood Chain
- Chain ID
- 4663
- RPC
- https://rpc.mainnet.chain.robinhood.com
- Currency
- USDG
- Decimals
- 18
- Explorer
- https://robinhoodchain.blockscout.com
- Type
- Arbitrum Orbit L2
- Testnet
- 46630