Swap and limit orders

02A market swap

1. Pick the token you pay with and the token you want. MAX fills in your whole balance.
2. Type the amount. The Quote panel shows the exchange rate, the minimum you will receive, the pool fees and price impact, and how many pools the route considered.
3. Choose a slippage tolerance. It is the most the price may move against you between quote and execution before the trade refuses to go through. 1 to 3 percent is normal for liquid pairs.
4. Press Execute swap and sign.

With 'all versions' selected, the router looks at every pool on both v3 and v4 and takes the route that pays out the most, including routes through middle tokens. Pick v3 or v4 in the top bar to restrict it.

03Safe routing

Safe routing is on by default. A route may pass only through SOUL, KCAL, TAZ and tokens whose supply is capped and fully minted. It never goes through a token whose owner can still mint more, because new supply sold into that token's pools can empty them at any moment. Direct swaps are never affected. When the router skips a route that would pay more, the Quote panel says so.

To use every pool, tick Allow risky routes under the slippage setting. Your choice is saved in this browser. A risky route is marked in red in the Quote panel and in the confirmation.

If the owner of the token you buy or sell can still mint more, the Swap page warns you in red, whichever routing you use.

04Pool fees and price impact

Two things make a swap pay out less than the pool's price. The pool fee is the share of what you pay in that the pool's owner set. Price impact is your own trade moving the pool's price as it goes through: the more you pay in next to what the pool holds of the token you pay with, the more the price moves against you. The Quote panel shows both before you sign.

Every quote is priced on the pool as it stands now. If you quote a swap and then quote the way back before swapping, the second quote pays the fee and the impact again on the same pool. In a pool with a 2 percent fee, a trade about 3 percent the size of what the pool holds of the token you pay in loses about 5 percent each way, so the two quotes together come back to roughly nine tenths of what you started with. Actually swapping and then straight back costs less: your first trade moves the pool's price in your favour for the return, so if nobody else trades in between you lose mostly the two fees.

05Choosing a pool

The router takes the route that pays out the most, which is usually the deepest pool. When a pair has more than one pool, the Quote panel lists each of them with its fee, its depth, what your amount would get there and its price impact, so you can see why the router chose as it did. Pick one to swap through that pool alone, or leave Best route (auto) selected. The Swap link next to each pool on a token's page, and Swap in this pool on a pool's page, open Swap with that pool already picked. If that pool is on a DEX version the top bar leaves out, the link switches it to all versions first.

06What the fee pays for

Every pool charges the fee its owner set, 0.30 percent on most pools. That fee is split four ways by the chain: part stays in the pool and compounds, part goes to the pool's owner, part goes to people staking the input token in Holder rewards, and part goes to the Saturn treasury. The exact split is a setting on the chain and can change.

07Split across pools

Tick Split across pools and a big swap can be shared between up to four pools of the same pair when that pays more; when it does not split, it says why. It is one transaction and one signature, each part with its own minimum: if any part cannot fill, nothing is swapped.

08A limit order

A limit order waits for a price instead of taking the one you see. It works on v4 pools only. You deposit the input token, set the minimum output you will accept, optionally a maximum, an expiry, and a bounty of up to 5 percent. Bots watch the chain and execute the order the moment the pool can pay your minimum, keeping as their bounty your chosen share of whatever came in above that minimum, so you never get less than you asked for. Nothing happens until the price is right, and you can cancel any time to get the deposit back.

A limit order needs a pool that already exists for the pair. The Limit tab only lists pairs with a direct v4 pool.