Portfolio Turnover Quant Interview Guide
Portfolio turnover quant interview guide covering turnover definition, rebalance frequency, costs, signal decay, examples, and controls.
Candidates connecting signal changes to trading, costs, and capacity.
Turnover measures trading activity
Portfolio turnover captures how much the portfolio changes over a period. High turnover can consume signal edge through spreads, impact, and fees.
Turnover comes from signal and rules
Noisy signals, frequent rebalancing, tight tracking targets, and aggressive optimizers can all increase trading activity.
Concrete example
A daily model with small forecast changes may trade constantly unless the process uses thresholds, cost-aware optimization, or slower signal decay assumptions.
Control turnover deliberately
Use turnover penalties, rebalance bands, trade thresholds, holding-period rules, and cost estimates to keep activity aligned with expected edge.
Common mistakes
Candidates often evaluate gross signal quality without turnover. A high-turnover signal must clear a much higher implementation bar.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.