Implementation Shortfall Interview Guide
Implementation shortfall interview guide covering decision price, execution price, delay cost, fees, opportunity cost, and examples.
Candidates measuring execution cost against decision price.
Implementation shortfall starts at the decision price
Implementation shortfall measures the cost between the portfolio decision and the realized execution, including trades that do not complete.
It includes more than filled price
The calculation can include spread cost, market impact, delay cost, commissions, taxes, and opportunity cost from unfilled quantities.
Concrete example
If a manager decides to buy at 50, fills half at 50.30, and the unfilled half later rallies, both fill cost and missed opportunity matter.
It is useful for urgency tradeoffs
Shortfall helps compare aggressive execution, passive execution, and staged execution against the original investment decision.
Common mistakes
Candidates often ignore missed fills. In shortfall analysis, unexecuted shares can be costly when the market moves away.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.