Price improvement occurs when an order is filled at a better price than the one requested or displayed — a buy executed below the expected level, or a sell above it. It is the positive counterpart of slippage and arises when the market moves favourably between order submission and execution, or when a broker's aggregation finds a better quote among competing liquidity providers.
Execution reports often express improvement in pips or in account currency, and some brokers publish aggregate statistics on how often orders receive it as part of best-execution reporting. Price improvement should be understood as a by-product of market conditions and routing quality, not as something predictable on any individual trade.
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Guide
How the Options Market Reaches the Spot Price
Option positions have to be hedged, and hedging means trading spot. What that flow is, why it clusters near certain rates, and why almost everything said about it is an estimate.