hardConceptDesignScenarioMidSeniorStaff
How does your order placement change on a venue that allocates pro rata within a price level instead of first in, first out?
6 min readUpdated 2026-08-15
Answer
Short answer
Queue position stops being worth anything and displayed size becomes the thing that earns fills, so you quote larger than your true intention, reprice freely because there is no queue to lose, and cap total displayed size against real risk appetite because a single large aggressor can fill all of it.
Mention matching rules where it changes the risk, the owner, or the next check.
Was this answer helpful?
Likely follow-ups
- Why do venues in some products choose pro rata at all, given that price-time is simpler?
- How would you size a resting order if you wanted an expected fill of 500 lots and the level holds 8,000?
- What does a hybrid rule that gives part of the allocation to the first order at the level do to your placement?
- How does over-display across several price levels combine into a position you did not intend?
Related questions
- A customer cancels a twelve-month policy after four months. How much do you refund?hardAlso on pro-rata5 min
- A transform has been writing wrong revenue figures for three days and six downstream tables have consumed it. How do you backfill the corrected data without double-counting anything?hardSame kind of round: scenario4 min
- Your consumer-driven contract test passes in CI, but production rejects a request because a supposedly optional field is missing. What did the contract testing actually miss?hardSame kind of round: concept4 min
- Your error budget burn alert pages every few hours, but half the time nobody outside the team has noticed anything. How do you tune it without simply making it quieter?hardSame kind of round: concept5 min