Browse Investing

Compounding, Effective Rates, and Reinvestment

Investment terms for compounding, effective rates, reinvestment assumptions, and doubling-time rules.

Compounding, Effective Rates, and Reinvestment terms explain how investment results are measured, compared, annualized, compounded, distributed, or translated into yield language.

Use this branch when the question depends on the exact return formula, time period, reinvestment assumption, fee treatment, tax treatment, or income-versus-price return split.

Key Terms in This Branch

TermUse it for
CompoundingA measurement term for comparing investment income, growth, or total performance.
Effective Interest RateA measurement term for comparing investment income, growth, or total performance.
Effective YieldA measurement term for comparing investment income, growth, or total performance.
Reinvestment RateA measurement term for comparing investment income, growth, or total performance.
Rule of 69.3A term page that narrows this branch to a specific investing concept, evidence source, or decision point.

What to Check

Check the formula, measurement period, compounding convention, cash-flow timing, reinvestment assumption, fees, taxes, currency, and whether the result is historical, expected, quoted, or realized.

Common Mistakes

  • Comparing returns from different periods or compounding conventions.
  • Treating quoted yield or expected return as the same as realized performance.
  • Ignoring fees, taxes, currency, reinvestment, and cash-flow timing.
  • Mixing income return, price return, and total return without labeling each measure.

This page is educational and does not recommend a specific investment strategy, security, tax treatment, or account choice.

In this section

Choose a subsection first. Deeper term pages live inside each subsection, which keeps large topic hubs readable.

Compounding

Compounding adds earned returns to principal so future returns are calculated on a growing investment base.

Effective Interest Rate

The effective interest rate converts a stated rate into the actual annual rate after compounding frequency is included.

Effective Yield

Effective yield measures investment income after compounding, making stated yields more comparable across payment schedules.

Reinvestment Rate

The reinvestment rate is the return assumed or earned when interim cash flows are put back to work in an investment strategy.

Rule of 69.3

The Rule of 69.3 estimates how long an investment takes to double when growth is modeled with continuous compounding.

Revised on Sunday, June 21, 2026