On Polyester, buyers can choose whether trading fees are paid in the base asset or the quote asset, when the market supports both options. Sellers always pay fees in the quote asset.
What Are Base and Quote Assets
Every spot market on Polyester consists of two assets:
- The base asset is the asset being bought or sold.
- The quote asset is the asset used to price the trade.
Example: In BTC/USDT, BTC is the base asset and USDT is the quote asset.
Where to Change Base vs Quote
The base vs quote selection is available directly on the order form for markets that support the option.
When Buy is selected, a toggle appears near the bottom of the order form allowing users to choose the ‘fee source’.
Base vs Quote Explained (With Examples)
Example 1: Buyer pays fee in base (fee shaved from what they receive)
A user places a buy order spending 100,000 USDT to buy BTC. Trading fee is 0.10%.
- Gross BTC bought at market: 1 BTC
- Fee (0.10% of 1 BTC): 0.001 BTC
- BTC received: 0.999 BTC
- USDT spent: 100,000 USDT
What happened: The fee is taken out of the asset they are receiving. Their position size is slightly smaller because part of the BTC is used to pay the fee.
Example 2: Buyer pays fee in quote (fee taken from spend)
A user places a buy order spending 100,000 USDT to buy BTC. Trading fee is 0.10%, paid in quote.
If fee is deducted from the order (default):
- Fee: 100 USDT
- USDT used for purchase: 99,900 USDT
- BTC received: 0.999 BTC
- USDT spent: 100,000 USDT
If fee is charged on top (optional setting):
- BTC purchased: 1 BTC
- Fee: 100 USDT
- Total USDT spent: 100,100 USDT
- BTC received: 1 BTC
What happened: Paying in quote lets each user choose whether the fee reduces the order size or is added on top, depending on their trading settings.