Why Does a Larger Fraxswap Swap Get a Worse Rate?

Fraxswap gives a larger swap a worse rate because each added unit of input shifts the pool’s reserves further from their starting balance. The fee is a separate, fixed percentage; the extra loss comes from trade size relative to available reserves, so the same order has less impact in a deeper pool.

How Reserve Shifts Change Your Output

A constant-product pool holds two token reserves, and their product, x·y = k, sets the price curve. If the pool starts with x units of your input token and y units of the token you want, a larger input pushes the reserves further along that curve: you receive progressively less output for each additional unit.

For input Δx and fee rate f, the estimated output is (Δx·(1−f)·y) / (x + Δx·(1−f)). The formula uses the input after the fee to calculate output; the fee itself remains in the pool. Uniswap v2 Core whitepaper (2020), by Hayden Adams, Noah Zinsmeister and Dan Robinson, describes this fee-adjusted constant-product calculation for its pair design. It explains the mechanism, though a live quote can also depend on the route and current reserves.

When choosing a route, compare pool reserves before sending the trade. The Fraxswap liquidity in a candidate pool matters because deeper reserves make the same order a smaller share of the pool, usually reducing the price movement you cause.

Separate the Fee From Price Impact

The fee is charged as a percentage of the swap, while price impact grows with the size of your input relative to the pool. A quoted rate can therefore worsen even when the fee has not changed. The app’s price impact estimate shows the expected effect of your trade on the pool price.

  • Fee: the pool’s percentage charge on the trade.
  • Price impact: the rate change caused by moving the reserves.
  • Slippage: the difference between the estimate and execution if conditions change before confirmation.

These are distinct: the fee applies to the swap, price impact follows from its size, and slippage can add uncertainty between quote and execution. For example, if a quote worsens as you increase an order while the fee stays constant, the pool’s reserves are likely driving the difference.

Choose a Sensible Trade Size

For a large order against thin reserves, I would compare routes or use a longer execution window instead of sending one instant swap. Splitting an order can help you manage execution, but repeated swaps against the same pool still move its reserves and incur fees; splitting alone does not remove price impact. A time weighted order, such as a TWAMM order where available, spreads execution over time and can reduce the immediate demand placed on one pool.

Use the quoted impact and reserve depth to judge whether the rate is acceptable: deeper pools absorb more size, while small pools move sharply as Δx approaches x. The fee tells you the pool’s charge; the reserve shift tells you why your larger swap gets a worse rate and whether to reroute or spread it out.

Comments

Post a Comment

Popular posts from this blog

Should You Split a Large Cross-Chain Swap?

Splitting a large cross-chain swap can improve its average price when each smaller trade moves a shallow pool less. But separate swaps can add network fees and time. Compare the amount you expect to receive after all costs, and check whether the route offers automatic streaming before splitting it yourself. What changes when you split the order? Price impact is the change in a pool’s price caused by your trade. A large trade can move that price against you as it uses available liquidity. Smaller trades may reduce that effect, especially in a pool with little liquidity. Manual splitting means sending several separate swaps. Each may need its own transaction on the source and destination chains, so you can pay extra network fees and wait for each one. Some services also charge a per-swap fee, so check the displayed breakdown before deciding. Automatic streaming divides one order into smaller trades over time, while keeping one wallet deposit and one final payout. When a route offers this...
Read more

Why is slippage unpredictable in thin-liquidity swaps?

Thin liquidity makes slippage unpredictable because a trade can move a pool’s price while it executes; say, a $1,000 order may use up a large share of a small pool. The quoted output is an estimate at one moment, not a promise that the same price will still be available when the transaction lands. Slippage grows when a trade moves the price Slippage is the difference between the price you expect and the price you actually get. In a liquidity pool, a large trade relative to the available reserves changes the reserve balance and therefore the price; the smaller the pool, the more each trade can move it. That price movement is called price impact. It is already reflected in a route’s estimated output. Slippage tolerance is different: it sets how much worse the final output may be than the quote before the transaction reverts. how a wallet swap runs through ParaSwap explains the wallet flow; here, the key question is how much the route’s price may shift before execution. Thin liquidity ma...
Read more

Why Do Swap Gas Costs Vary Between Settlement Batches?

Gas costs vary because each settlement batch contains a different mix of orders and on-chain actions, and it executes under that moment’s network conditions. A solver pays to submit the settlement transaction, so a batch that needs extra liquidity calls or runs during a busy period can cost more than one that matches trades directly. What determines a batch’s gas cost? A batch is a group of eligible orders that solvers try to settle together. They build candidate solutions, then compete to submit a valid one; the winning settlement may combine trades between users with trades routed through on-chain liquidity. For someone used to a centralised exchange, the key difference is that the exchange’s internal matching engine is replaced by this off-chain competition and on-chain execution. With the cowswap interface , you sign an order from your wallet rather than submitting a transaction to execute the swap yourself. A solver submits the settlement and pays its gas. That means you generally...
Read more