Each trading pair comprises Sell and Buy assets. So to set a trading pair you have to select the asset you want to sell and the one you want to buy in exchange by looking for the available assets in the drop-down lists.
Selecting Sell asset
Here you can see available assets for Sell, i.e. the ones you can borrow from Credit Buckets to amplify your position. Under Traded Assets, you see USDC since the USDC Bucket is selected at the top. Under Available in other buckets, there are assets that you can borrow too, and if you select one of them, the Bucket will automatically switch to the required one. By default, Primex selects the Bucket with the lowest Borrowing Rate.
Selecting Buy asset
Under Traded Assets, you will see the assets you can buy when borrowing funds to sell from the chosen Credit Bucket. Under Available in other buckets, you see the assets that can be bought when borrowing from other buckets (the Bucket will switch automatically if you click on an asset).
NOTE: For Spot 1X and Swap the process is almost identical except that you won’t see the breakdown of Traded and Available assets, but just single lists for Sell and Buy.
Long vs Short position
It's important to stress that when trading with margin on Primex you can open both Long and Short positions.
In a nutshell, Long is when you anticipate the price of the asset to go up, so you wish to Buy it at a lower price and Sell at a higher price later to make profits.
On the contrary, when opening a Short position, you expect the price of the asset to drop, so you Sell it at some point to Buy it later when it's cheaper.
Let's say we have asset A and asset B. On Primex Long A means Short B and vice versa, so you always Long the Buy asset and Short the Sell asset.
In the example below, to switch between Long and Short WBTC against USDC you can switch Sell and Buy:
