All In Cost
All in cost is the total trading cost including execution costs (spread, slippage) plus fees. It is the cost you must overcome for a trade to be profitable.
Definition
All in cost is the total cost of trading after you include both microstructure costs and fees.
What it includes
• Execution costs, captured by measures like effective spread and slippage.
• Platform trading fees (per contract or percent based).
Why it matters
A trade idea is only actionable if the expected edge exceeds all in cost. In prediction markets, price moves are bounded, so costs are a large part of the game.
Common pitfalls
Looking at spread only: Spread can understate real cost when depth is low and you slip across levels.
Ignoring two sided costs: Many strategies pay costs on both entry and exit.