Core concepts / Positions and P&L

#What a position is made of

• Shares. How many units of the outcome you hold.
• Entry price. The average price you paid per share.
• Cost basis. Shares multiplied by entry price. What you put in.
• Current value. What the shares are worth at the market’s present price.

For an open position, profit and loss is current value minus cost basis, and the percentage shown is that difference over the cost basis. Green is a gain, red a loss, and the app colours the figure accordingly.

For a closed one the app does not recompute anything. It shows the realised figure the venue reports, alongside the total you originally paid. That way a closed position cannot drift as prices move afterwards, and it agrees with what the venue itself says you made.

#Resolution

When a market resolves, each share of the correct outcome is worth $1.00 and each share of the wrong one is worth nothing. You do not have to hold to resolution; selling early realises whatever the position is worth at that moment.

#Why a brand new position can show a loss

This surprises almost everyone, and it is not a fee and not a bug. It comes from the spread.

Buying fills against the asks, the prices sellers are asking. Selling fills against the bids, the prices buyers are offering. The bid is always below the ask, so the instant you buy, the price at which you could sell is lower than the price you just paid. Value the position at the bid and it is immediately worth slightly less than it cost.

Best ask   0.42     you buy here
Best bid   0.40     you would sell here
Spread     0.02

Buy $5.00 at 0.42        ->  11.90 shares
Sell 11.90 at 0.40       ->  $4.76
Round trip                   -$0.24, about -4.8%

Nothing moved in the market. That $0.24 is the cost of crossing the spread twice, and it is why a $5 buy sold straight back does not return $5. Wider spreads in thin markets make it larger; deep, liquid markets make it small.

#Depth makes it worse than the top of the book suggests

The example above assumes your whole order fills at the best price. If your order is larger than the size resting there, the remainder fills at worse prices and your average entry is higher than the quote. The app works out your share count by walking the real book rather than dividing by the quoted price, so the estimate you see before confirming already accounts for this.

#Where positions are shown

Open positions appear on the market page for the market they belong to, and all of them together on the profile page. The profile page also totals them into a portfolio value alongside your cash balance.

Position and price data is read from the venue rather than stored by the app, so it reflects the venue’s own view of what you hold. Nothing here is cached in a way that could go stale against it.