CluenexWhat is time-weighted return?
Time-weighted return (TWR) is a performance calculation that measures the compound rate of growth in a portfolio by removing the distorting effects of cash inflows and outflows. It reflects how one dollar invested at the start of a period would have performed if no additional money was added or removed.
To calculate TWR, you divide the overall investment timeline into separate sub-periods every time you deposit or withdraw cash. You calculate the percentage return for each sub-period individually, and then geometrically link those sub-period returns together. Because each sub-period is weighted equally by time rather than by the dollar amount invested, an influx of new capital right before a market drop will not drag down the calculated rate of return.
Institutional investors, mutual funds, and performance standards rely on TWR to evaluate investment strategies. The Global Investment Performance Standards (GIPS) established by the CFA Institute require firms to use time-weighted returns for liquid public equity portfolios. This standard ensures that fund managers are judged strictly on their asset allocation and security selection, rather than on client deposit schedules over which managers have no control.
What is money-weighted return?
Money-weighted return (MWR) is a performance metric that accounts for the timing and dollar size of all cash deposits, withdrawals, and ending account balances. It is mathematically identical to the internal rate of return (IRR) used in corporate finance.
Rather than breaking the holding period into isolated sub-periods, MWR calculates the single discount rate that sets the net present value of all cash flows equal to zero. When you deposit money into your account, it is treated as a negative cash flow. When you withdraw money or calculate your ending balance, it is treated as a positive cash flow.
Because MWR gives greater weight to periods when your account balance is larger, it captures your actual personal dollar experience. If you invest heavily right before a major bull market, your MWR will be higher than your TWR. If you deposit significant capital at a market peak right before a pullback, your MWR will suffer, even if your underlying stocks perform reasonably well over the full period.
A step-by-step calculation example with real numbers
To see how TWR and MWR diverge, consider a one-year retail portfolio spanning January 1 to December 31, 2025. This example shows how a poorly timed deposit changes personal results without changing the strategy return.
Imagine an investor starts with $10,000 on January 1, 2025. Over the first six months, the portfolio grows by 25.0% to $12,500 on June 30. Encouraged by the gain, the investor deposits another $10,000 on June 30, bringing the starting balance for the second half of the year to $22,500. Over the final six months, the portfolio declines by 20.0%, leaving an ending balance of $18,000 on December 31.
Calculating Time-Weighted Return (TWR)
First, calculate the return for sub-period one, which runs from January 1 to June 30:
- Sub-period 1 return = ($12,500 - $10,000) / $10,000 = +0.25 (or +25.0%)
Next, calculate the return for sub-period two, which runs from June 30 to December 31, starting with the post-deposit balance of $22,500:
- Sub-period 2 return = ($18,000 - $22,500) / $22,500 = -0.20 (or -20.0%)
Finally, multiply the compounding factors and subtract one:
- TWR = (1 + 0.25) * (1 - 0.20) - 1
- TWR = (1.25 * 0.80) - 1 = 1.00 - 1 = 0.0%
On a time-weighted basis, the investment strategy broke even at 0.0% over the full year. A 25% gain followed by a 20% decline returns capital to its original level.
Calculating Money-Weighted Return (MWR)
Now, look at the actual cash flows to calculate the money-weighted return. The investor contributed $10,000 at day zero and $10,000 at month six, totaling $20,000 in deposited principal. The final portfolio balance is $18,000, meaning the investor lost $2,000 in actual cash.
To find the annualized MWR (r), solve the net present value formula where cash outflows equal discounted inflows:
- $10,000 + $10,000 / (1 + r)^0.5 = $18,000 / (1 + r)^1.0
Solving this quadratic equation yields an annualized rate (r) of -13.2%. While the time-weighted return is 0.0%, the money-weighted return is -13.2%. The investor lost money because more capital was exposed to the 20% drop than to the 25% gain.
Time-weighted versus money-weighted returns: A direct comparison
Both metrics provide valuable portfolio insight, but they answer completely different questions for individual investors.
| Attribute | Time-Weighted Return (TWR) | Money-Weighted Return (MWR) |
|---|---|---|
| Primary Purpose | Measures pure strategy and stock picking skill | Measures personal wealth creation and dollar growth |
| Impact of Cash Flows | Removed by splitting history into sub-periods | Heavily influenced by deposit size and timing |
| Mathematical Base | Geometric compounding of holding period returns | Internal rate of return (discount rate where NPV = 0) |
| Benchmark Comparison | Direct and fair against indexes like the S&P 500 | Inaccurate for comparing against market indexes |
| Data Needed | Daily or cash-flow-dated account valuations | Cash flow dates, amounts, and ending balance |
| Brokerage Label | 'Investment Return' or 'Time-Weighted Rate' | 'Personal Rate of Return' or 'Performance Return' |
Why the gap between TWR and MWR matters for retail investors
The difference between TWR and MWR reveals the behavioral cost or benefit of your cash flow timing. Financial researchers frequently refer to a negative spread between MWR and TWR as the behavior gap.
When retail investors chase rising markets, they tend to deposit more savings after a long run of strong gains. Those larger balances then suffer when the market corrects. In that scenario, their personal money-weighted return falls far short of the fund or index time-weighted return.
Conversely, disciplined investors who practice dollar-cost averaging often generate a money-weighted return that exceeds their time-weighted return during volatile sideways markets. By putting consistent sums to work after price pullbacks, they buy more shares at depressed levels, boosting the cash generated when prices recover.
If you want to evaluate whether your active equity strategy beats passive investing, you must compare your TWR to the benchmark. Comparing an active portfolio's MWR to the S&P 500 total return creates an unfair comparison. A rising market will make an MWR look artificially depressed if you added significant cash halfway through the year, masking genuine outperformance in stock selection.
Tracking stock research against benchmarks requires isolating timing noise. For example, the Cluenex research platform records stock verdicts and measures its published track record at cluenex.com/track-record/ against the S&P 500 using transparent valuation rules to judge stock analysis quality directly.
Where each calculation fails and common mistakes
Neither calculation provides a complete picture when used in isolation, and retail investors frequently misinterpret the outputs.
First, calculating an exact TWR requires knowing the exact market value of your portfolio immediately before every single cash deposit or withdrawal. If you contribute $200 every two weeks from your paycheck, calculating a true daily-valuation TWR requires 26 separate sub-period valuations each year. Without automated software, manual recordkeeping becomes tedious.
When daily valuations are unavailable, analysts often substitute the Modified Dietz method. The Modified Dietz method weights cash flows by the proportion of the period they were present in the account, providing a close approximation of TWR without requiring daily account valuations.
Second, MWR can produce misleading results if your cash flows are erratic. In rare situations where cash flows alternate between large positive and negative values, the mathematical IRR equation can yield multiple internal rates of return or fail to resolve. MWR also punishes the investor for deposits driven by life circumstances, such as investing an annual work bonus or an inheritance, regardless of whether the timing was an intentional market call.
Third, investors often confuse dollar profits with percentage returns. A portfolio can have a positive money-weighted return while displaying a negative time-weighted return if a large sum earned a modest gain while a small sum suffered a heavy loss. Reviewing terms in a financial glossary helps clarify how compounding math affects reporting.
What this means for you
If you manage your own portfolio through a standard brokerage account, you do not need to calculate these equations by hand every week. You do need to know which number to check when evaluating your financial health versus your investing skill.
Use this three-step framework when reviewing your annual investment performance:
- Check MWR to evaluate your personal savings goals: Look at your brokerage statement's personal rate of return to verify whether your money is growing at the annual rate required by your retirement plan. If your retirement model assumes a 7% annual growth rate, your money-weighted return tells you whether your actual balance meets that expectation.
- Check TWR to audit your stock selection skill: When comparing your performance against an index fund or managing your portfolio diversification, look exclusively at your time-weighted return. If your active picks generate an 8% TWR while the broad market index generates 11% over the same timeframe, your stock selection underperformed, regardless of what your cash deposits did to your account balance.
- Identify your behavior gap: Subtract your TWR from your MWR. If your MWR is consistently lower than your TWR over three to five years, your deposit habits are hurting you. Stop trying to time cash infusions around news headlines, and automate your contributions on a fixed calendar schedule instead.