Before following this guide, make sure you select the SPOT market!
From Main Menu, go to your Trading Dashboard. Or, use this link: https://trade.quoinex.com
To place orders, locate the Order Entry panel (top left of dashboard by default).
Fill out the Quantity field. This is how much you want to buy or sell. Placing a market order means you agree to buy or sell at market price, so there is no price choosing here.
Cost, average price, and fee are all collapsible in order to show more details.
You can check the price on top of the dashboard, or in the Orderbook on the right. The lowest price in red is the best market ask (how much you will spend to buy 1 BTC, or how much people are asking for 1 BTC). The highest price in green is the best market bid (how much you can get from selling 1 BTC, or how much people are bidding for 1 BTC). Market orders are executed with these prices. The difference between them ($3.67 in the screenshot) is called spread. The bigger the spread, the more volatile the market.
Average price here is the best price right before the order is submitted. Actual price when your order is matched can be a different one - see Slippage. Fee in this case is trading fee and zero, but if you are trading a non-base currency pair, fee is 0.25% of trading amount - see Fees.
Click Buy or Sell to place the order. System will ask you to confirm again. Check everything over once again, then click Submit Order to finalize.
Once you place a market order, several things happen. Your balance in both accounts (base and quote currencies) will change. The new order will appear in Orders panel (bottom right of dashboard by default).