Every round has one shared pool. Every back goes into it, and the people who picked the winner share it out at the end.

Your payout is your share of the winning side

This is the whole model in one sentence:
If your trader wins, you receive the same share of the pool as your stake was of everything staked on that trader.
So if 1,000 XP in total was backed on the trader that wins, and 100 XP of that was yours, your stake was 10% of the winning side. You take 10% of the pool, after the platform fee. Nothing else affects it. Not how many people backed, not when you backed, not how big the pool got. Only your share of the winning side.

The multiplier

The multiplier next to each trader turns that into a number you can read at a glance: how much your stake would be worth if that trader won, based on the pool right now.
Take a pool of 10,000 XP. After the platform fee (300 XP), 9,700 XP is left to share out: The fewer people on a trader, the fewer people to share with, and the higher the multiplier.

There is no bookmaker

Incept does not quote you a price and take the other side of your back. You buy a share of the winning side. Your payout depends on how the pool finishes up. Other backers take the other side.

The multiplier moves until backing closes

The multiplier you see is a snapshot of the pool as it stands, not a price you lock in.
  • More people back your trader and the multiplier falls, because more people will share the pool with you.
  • More people back the others and your multiplier rises.
  • When backing closes the pool freezes. The multiplier at that moment is the one that pays.
The multiplier shown when you place your back is not a guarantee. It can move in either direction until backing closes. Only the final multiplier matters.

What the multiplier does and does not tell you

A high multiplier means few people have backed that trader. That is all it means. It says nothing about whether the trader is any good. Those are two separate questions, and you want an answer to both: Next, see the full maths in How payouts are calculated.