Rate Conversion in Quant Interviews
Rate conversion in quant interviews for per-day, per-year, per-user, trade, event, and activity-rate estimates.
Candidates who make unit mistakes in estimation and market-sizing prompts.
Rates need time units
A rate is incomplete without its time base. Per day, per month, and per year can change an estimate by orders of magnitude.
Convert before multiplying
If one input is per day and another is per year, convert them to a common time base before combining them, or the final scale will be wrong.
Concrete example
If a user makes 2 actions per day, that is about 700 actions per year using 365 days. For rough estimates, 2 x 350 can be enough.
Track per-user versus total
Per-user rates become totals only after multiplying by user count. Keep those units separate in the written decomposition.
Common mistakes
Candidates often mix daily and annual rates in the same line. Write the unit next to every rate until the final answer and check the requested period.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.