Price Improvement
Also known as: better-than-quoted fill, PI, execution improvement, positive slippage
What is it?
Price improvement is when your order fills at a better price than the one you saw or asked for. For a buy, that means a lower fill price; for a sell, a higher one. It is the opposite of slippage, where the price moves against you between order and fill.
Slippage (worse than quoted)
- Quoted offer to buy EUR/USD: 1.10520
- Actual fill: 1.10525
- Result: -0.5 pip against you
- Cost on a 1-lot order: about -$5
Price improvement (better than quoted)
- Quoted offer to buy EUR/USD: 1.10520
- Actual fill: 1.10515
- Result: +0.5 pip in your favor
- Saved on a 1-lot order: about +$5
Say you place a market order to buy EUR/USD with the offer showing 1.10520, but liquidity tightens for a moment and your broker fills you at 1.10515. You just got half a pip of price improvement on every lot. On a 1-lot order that is about $5 back in your pocket purely from a better fill.
You will not get improvement on every trade, but execution venues that route to deep liquidity and offer it consistently lower your real cost of trading over many orders.
Why it matters: It lowers your real cost per trade by filling you better than quoted, so the same strategy keeps more of its edge over many orders.
Price improvement = quoted price - fill price (for a buy); fill price - quoted price (for a sell)
Across many trades, consistent price improvement meaningfully lowers your cost base, even if any single fill barely moves the result.
Real-world example
You buy GBP/USD expecting a 1.27040 offer but fill at 1.27036, gaining 0.4 pips of price improvement, worth about $4 on a standard lot.
How SignalBots handles it
SignalBots Connector routes your orders to execution venues and surfaces your fill price versus the quoted price, so you can see when you get price improvement or slippage on the trades it places. See /risk-warning.
Pro tip
Track your average price improvement and slippage together across many fills - the net of the two is your true execution cost, not the headline spread.
Common pitfalls
Assuming a tight advertised spread means good execution while ignoring whether you actually get improvement or slippage at fill time.
Frequently asked questions
How is price improvement different from slippage?
Price improvement fills you at a better price than quoted; slippage fills you at a worse one. Both measure the gap between the price you saw and the price you got - improvement is the favorable side, slippage the unfavorable.
Why would a broker give me a better price?
When a broker routes to deep liquidity or a faster venue, the best available price can move in your favor in the moment between your order and the fill, passing that improvement on to you.
Can I rely on price improvement happening?
No. It depends on liquidity and timing and will not occur on every order, so your capital is at risk and you should never size a position assuming a better-than-quoted fill.
Does price improvement matter for small accounts?
Yes, proportionally. Fractions of a pip per trade add up across many orders, so a venue that improves fills regularly lowers your real cost no matter your account size.
How do I measure price improvement on my own trades?
Compare the price quoted when you submitted each order to the actual fill price, then average the difference across many fills to see whether your venue tends to improve or worsen your execution.
Trading involves substantial risk of loss. Historical and backtested results do not guarantee future performance. Read the full risk warning.