Slippage
Filling worse than the price you saw, by eating several levels of the book.
In the chapter
What you are looking at, before looking at anything
From the same chapter
- BidThe highest price someone will buy from you now. It is what you sell at.
- Ask / OfferThe lowest price someone will sell to you. It is what you buy at.
- SpreadThe difference between the two. The toll for getting in and out.
- Order bookThe two lists of intentions. It shows orders, not trades.
- LiquidityCapacity to absorb a trade without moving. Not fixed: it changes with the hour and the news.
- Aggressive / passiveWhoever crosses at market chose the moment; whoever posted a limit chose the price.
- LeverageTrading more notional than deposited. It does not improve accuracy: it multiplies consequence.