How to buy a cryptocurrency call option

A call option is an agreement that gives the option buyer the right, but not the obligation, to buy a specified amount of cryptocurrency at a specified price within a specific time period.

To learn more, read the Wikipedia article about call options, or the Investopedia call option entry.
Step 1
Register an account with AgoraDesk. You get a free and secure online cryptocurrency wallet. No additional apps are needed. If you already have an account, skip to the next step.
Step 2
Go to the main page. On the top bar of the website, select 'Trade options'. Then, select the cryptocurrency you want to trade by pressing the corresponding tab on the row above the ads table. For this example we'll choose BTC. To the left of the cryptocurrency selector you should select 'Call' options. In the left column you should then select the 'Buy' tab. If you wish to change the country,currency, payment method or specify the needed amount, click on the 'Show search menu' button, choose the desired parameters, and press the search button. If you're unsure how you want to pay, choose 'All online offers' as your payment method. The site will list traders available in your region.
Step 3
From the list of advertisements, choose one from a trader with a good reputation score and a high amount of trades. A green circle means the trader has been online today, a yellow circle means they have visited the site this week and a grey circle means that the trader hasn't been here for over a week. You can click the 'Buy' button to view more information about an advertisement.
Step 4
After you press the 'Buy' button you'll see more information about the advertisement, including the terms of the trade. Read through them before submitting the trade request, if you don't agree with them you can go back to the previous page and choose another advertisement. To start the trade, type in the notional value or the underlying BTC amount of the option and click the 'Send trade request' button to start the trade.
Step 5
Once you've started the trade, on your right side you'll see the section that will guide you through the trade's flow. The first thing that happens when you buy a call option, is that you need to pay the premium using the trade's payment method in the amount displayed on the trade page. If you fail to complete the payment within the payment window, the seller will be able to cancel the trade. Once you've completed the premium payment, press the 'I have paid' button. After the seller confirms they've received your premium payment, the option contract will activate.
Step 6
To your right you'll see a countdown timer that'll show you when the option expires. If your option is in-the-money and you exercise it, you'll receive the BTC equivalent of the difference between the notional value and the current market value of the underlying BTC.