FungibleRange

How it works

Fungible wrappers around concentrated liquidity are old: Gamma, Arrakis and the Alpha Vaults have run them for years. They all share a shape, and a defect that comes with it. The shape is a vault that sits outside the pool, holds a position, and is moved by a keeper.

The defect is that the moving is either discretionary, in which case depositors are trusting a manager, or mechanical, in which case it is predictable. A predictable rebalancer is a standing invitation. If liquidity re-centres whenever the price leaves a fixed band, anybody can compute where that happens, push the price there, and trade against a position they knew in advance was about to move.

The vault pays for the rebalance and the searcher takes the difference. Making the band larger helps once and then the same attack runs at the new boundary. This band is not fixed.

Every rebalance widens it, and quiet time narrows it back toward its base. So an attacker who forces a move has, by forcing it, made the next move harder to force and the position they wanted to pick off less concentrated. Run the attack repeatedly and it damps itself; stop, and the band tightens again on its own.

The width ends up tracking realised volatility, which is what a manager was being trusted to do by hand, computed from the pool's own ticks rather than from anybody's judgement. There is no keeper. Rebalancing happens inside whichever swap pushed the price out of band, which is also the swap that had a reason to.

There is no manager, no allowlist and no parameter anybody can change after deployment.

Using it

Uniswap v4 removed hookData from initialize, so per-pool parameters arrive out of band. Fix them for a pool key whose pool does not exist yet, then initialize. Nobody can change them afterwards, including you.

poolManager.initialize(key, startingSqrtPriceX96);

Parameters

This hook takes no per-pool configuration.

From TypeScript

npm i @hookforge/sdk

import {getHook, hookAddress, poolKeyFor} from "@hookforge/sdk";

const hook = getHook("fungible-range");
const key  = poolKeyFor({
  hook: hookAddress("fungible-range", 8453),   // Base
  currencyA: USDC, currencyB: WETH,
  tickSpacing: 60,
});

What it reverts with

The callbacks it claims

Uniswap v4 reads a hook's permissions from the low fourteen bits of its own address, which is why deploying one means mining a CREATE2 salt. This hook claims 2, so every deployment of it has an address ending in 0x1040.

• beforeInitialize
• afterInitialize
• beforeAddLiquidity
• afterAddLiquidity
• beforeRemoveLiquidity
• afterRemoveLiquidity
• beforeSwap
• afterSwap
• beforeDonate
• afterDonate
• beforeSwapReturnsDelta
• afterSwapReturnsDelta
• afterAddLiquidityReturnsDelta
• afterRemoveLiquidityReturnsDelta

It says what it is, on-chain

Nothing about a hook's address tells an indexer, a wallet, a router or an agent what the pool does, which is why hook discovery today is a curated list. This hook answers for itself, in one eth_call, with no registry in the loop.

cast call $HOOK "hookName()(string)"    # FungibleRange
cast call $HOOK "specURI()(string)"     # https://fungible-range.pages.dev/hook.json
cast call $HOOK "hookTags()(string[])"  # liquidity, concentrated, rebalancing, keeper-free, no-admin

Build, test and deploy

git clone --recurse-submodules https://github.com/nirholas/fungible-range
cd fungible-range
forge build && forge test

# Dry run: mines the salt, prints the address, sends nothing.
forge script script/Deploy.s.sol --rpc-url $RPC_URL

# For real.
forge script script/Deploy.s.sol --rpc-url $RPC_URL --broadcast --verify

Try it

This is the hook running, not a picture of it. Connect a wallet on a chain it is deployed to, or bring the whole stack up locally in one command and use it with no funds and no wallet risk at all.

git clone --recurse-submodules https://github.com/nirholas/fungible-range
cd fungible-range

anvil &
forge script script/DeployLocal.s.sol --rpc-url http://127.0.0.1:8545 --broadcast \
  --private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80

node web/build.mjs && npx serve web/dist