Copy and fade
See a call you like? Copy it. Think they're wrong? Fade it. Either way it's your own position, with your own money, at today's price.
Copy
Copy puts you on the same side. You get in at the current price, not theirs, so if the market has moved since their call your payout is different. The feed shows both prices so you can decide.
Fade
Fade puts you on the other side. It works on two-way markets (Yes/No, or two teams). On a market with a draw there's no single other side, so Fade isn't offered.
Your stake, your price
Copy opens the call panel with your default stake, not theirs. Change it before you confirm. Their stake is never shown unless they've chosen to show it.
Who gets the credit
The person you copied or faded is told, and copies count on their profile (“1.4K copies of their calls”). A copy only counts if it's a real filled order on the same market and side; the server checks.