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Lesson 5 of 5 6–9% of the exam

Fund of funds fees, survivorship bias and backfill bias

A fund of funds charges its own fees on top of the hedge funds' fees, so the investor pays twice in exchange for diversification, due diligence and access. Hedge fund indexes overstate typical returns because failed funds drop out (survivorship bias) and managers add only good past records (backfill bias).

6 min cram, 26 min full read. Based on the 2027 CFA® Program Level I curriculum, Alternative Investments, Learning Module 2. Also part of the 2026 curriculum, so it applies to the November 2026 exam too.

Tailor this to you: take the self-assessment

Before this: Calculating returns after fees: management, incentive, hurdle and high-water mark

On the exam

  • Describe the performance appraisal of alternative investments
  • Calculate and interpret alternative investment returns both before and after fees

Calculate a fund of funds net return and describe the index biases. Expect one numeric item that applies two layers of fees, and one concept item that separates survivorship bias from backfill bias.

How deeply to learn each part
Know the idea
Understand it in general. It frames other topics, but you will not calculate with it.
Use it
Understand it well enough to solve a question with it. Recognize when it applies.
Memorize
Learn it by heart. The exam will not give it to you.

You know this one. The full lesson is folded away. The takeaways, formulas and checkpoint below are your quick refresher, and the checkpoint is a fair test of whether you still do.

You tested strong here. The full lesson is folded away. The takeaways, formulas and checkpoint below are your quick refresher, and the checkpoint is a fair test of whether you still know it.

Cram mode: the one-screen version of this lesson. Switch to Full for the explanations, worked examples and interactives.

What does a fund of funds cost you?

A fund of funds invests in other funds, so it has its own management and incentive fees on top of the fees the underlying hedge funds charge. This is a double layer of fees . The fund of funds sees only what is left after the first layer, so the second layer is charged on that net return.

Return after the hedge fund layer Use it
r1=r−m1−p1 rr_1 = r - m_1 - p_1\,r
Investor return through a fund of funds Use it
ri=r1−m2−p2 r1r_i = r_1 - m_2 - p_2\,r_1

These forms assume fees calculated independently, management fees on beginning assets and a positive return. With a loss there is no incentive fee in that layer.

Rearrange itFund of funds, two layers of fees: solve for any input
The question asks for
Hedge funds earn 15.00% before fees and charge 2.00% plus 20.00% of the return (calculated independently, management fee on beginning capital). A fund of funds charges 1.00% plus 10.00% of the return it receives, also calculated independently. The investor's net return is closest to:

r₁ = 15.00% − 2.00% − 0.2 × 15.00% = 10.00%; r_i = 10.00% − 1.00% − 0.1 × 10.00% = 8.00%

Investor net return, r_i8.00%

On your calculator
  1. 15×0.8−2=STO1after the hedge fund layer 10
  2. RCL1×0.9−1=STO28

STO store · RCL recall a stored number

  1. 15ENTER0.8×2−STO1after the hedge fund layer 10
  2. RCL10.9×1−STO28

ENTER enter (on the HP, puts the number on the stack) · STO store · RCL recall a stored number

What the second layer of fees buys
Fund of funds versus a single hedge fundthe investor pays two sets of fees
  • Manager selection and monitoring Memorize due diligence done for you
  • Diversification across funds Memorize one fund's loss offsets another's gain
  • Access to closed funds Memorize the only way in to some managers
  • Easier redemption Memorize cash buffers and special terms, sometimes

Why accept the extra cost? The extra layer buys manager selection and monitoring, diversification across funds, access to funds closed to new investors and, sometimes, easier redemption than a direct hedge fund investment. The example above assumes all the underlying funds earn the same return, which will not be true in practice. A good fund of funds may add value by selecting managers, and a poor one adds only cost.

When a fund of funds holds several hedge funds, it charges its fees on the combined portfolio, not fund by fund. Gains in one fund offset losses in another before the incentive fee is set.

Fund of funds fees on the combined value Use it
RFoF=V1 m2+max⁡[0,  (V1−V0) p2]R_{FoF} = V_1\,m_2 + \max\left[0,\; (V_1 - V_0)\,p_2\right]
InteractiveFund of funds: two layers of fees

Try this 0 of 2

  • Set the fund of funds' own fees to zero
  • Find a gross return at which fees take more than half of it

Hedge fund fees

Fund of funds fees

Investor's net return8.00%
After the first layer10.00%
Cost of the second layer2.00 pts
Fees as a share of gross46.7%
Show working

Hedge funds: 15.00% − 2.00% − 20% × 15.00% = 3.00% → 10.00%

Fund of funds, on what it receives: 10.00% − 1.00% − 10% × 10.00% = 1.00% → 8.00%

Total fees 7.00 points of a 15.00% gross return. Management fees are on beginning assets, so they come straight off the return.

Net return on your calculator
  1. 15×0.8−2=10, hedge fund net
  2. 10×0.9−1=8, investor's net return in %
  1. 15ENTER0.8×2−10, hedge fund net
  2. 10ENTER0.9×1−8, investor's net return in %

ENTER enter (on the HP, puts the number on the stack)

Two layers of fees, and indexes that flatter: adjust expectations down.

Why do hedge fund indexes look better than reality?

Investors who care about risk-adjusted returns with low correlation to common asset classes track alternatives through relative returns , a fund’s performance compared with that of similar investments. They compare a fund with a benchmark : an index or peer group with similar features. For alternatives, the benchmark needs care, because both the peer group and the way it is built can mislead.

Hedge fund indexes suffer from selection bias : the funds in the database are not a fair draw of all funds. Two forms matter.

Why hedge fund indexes flatter returns
Selection bias in hedge fund databasesboth biases push reported returns up
  • Survivorship bias Memorize funds that fail are dropped; only survivors remain
    • Cause poor performance, investor defections, closure
    • Effect average return overstated
  • Backfill bias Memorize a fund joins the index and its earlier returns are added
    • Cause managers launch several funds and report only the best ones
    • Effect average return overstated

With survivorship bias , the problem is that funds that do badly attract withdrawals and close, and then drop out of the database. Studies suggest a large share of hedge funds fail within the first few years. An index that holds only funds that still exist leaves out the failures, so investors form overly optimistic expectations of return.

With backfill bias , the problem is when and how a fund enters the index. A manager may launch several funds at once and put only the most successful ones into an index a couple of years after launch. Adding their earlier returns afterward, selectively, raises the average reported return.

BiasWhat happensEffect on index returns
Survivorshipfunds that close disappear from the databaseoverstated
Backfilla fund joins after a good start and its earlier returns are addedoverstated

Because of both biases, a hedge fund index may reflect only the funds that performed best early or that have not failed, rather than the average hedge fund.

Exam tip Failures vanish = survivorship. History arrives late = backfill. Either way, the index return is too high.

Fairer comparisons use like with like. For private equity and real estate, compare funds of the same vintage year, on an annual basis or since inception, because a composite benchmark can mislead when a fund is at a different life cycle phase from most of its peers. Compare hedge funds only with peers that follow the same strategy. And remember that lockups and illiquidity may stop an investor from acting on poor results, even when the comparison shows them.

Go deeper Survivorship bias outside hedge funds

The same bias affects any dataset built from today’s survivors: mutual fund databases that omit closed funds, and stock indexes tested only on companies that still exist. It comes back in the Quantitative Methods module on sampling and estimation.

Go deeper How much of the gross return do the two layers take?

In the 15% example the investor ends with 8.0%, so fees took 7.0 of the 15.0 points: about 47% of the gross return. A direct investor in the same hedge funds would keep 10.0%, and fees would take 5.0 points, one third. The comparison that matters is the extra 2.0 points against the value of the selection, diversification and access that the second layer provides.

Memorize this

MemorizeTwo layers of fees

Memory hook Net the first layer, then charge the second layer on what is left: the fund of funds only ever sees the net return.

Know it cold r1=r−m1−p1rr_1=r-m_1-p_1r, then ri=r1−m2−p2r1r_i=r_1-m_2-p_2r_1 (independent, positive returns). The second incentive fee is on r1r_1, not on rr.

MemorizeIndex biases

BiasWhat happensEffect on index returns
Survivorshipfunds that close drop out of the databaseoverstated
Backfilla fund joins after a good start; earlier returns addedoverstated

Memory hook Survivors only: the dead are missing. Backfill: only the winners get their history added. Both leave a better crowd than the real one.

Know it cold Fairer comparisons: same strategy, same vintage year for private funds, since-inception returns.

What the second layer of fees buys
Fund of funds versus a single hedge fundthe investor pays two sets of fees
  • Manager selection and monitoring Memorize due diligence done for you
  • Diversification across funds Memorize one fund's loss offsets another's gain
  • Access to closed funds Memorize the only way in to some managers
  • Easier redemption Memorize cash buffers and special terms, sometimes
Why hedge fund indexes flatter returns
Selection bias in hedge fund databasesboth biases push reported returns up
  • Survivorship bias Memorize funds that fail are dropped; only survivors remain
    • Cause poor performance, investor defections, closure
    • Effect average return overstated
  • Backfill bias Memorize a fund joins the index and its earlier returns are added
    • Cause managers launch several funds and report only the best ones
    • Effect average return overstated
Return after the hedge fund layer Use it
r1=r−m1−p1 rr_1 = r - m_1 - p_1\,r
Quick example

Hedge funds earn 12% gross and charge a 1% management fee on beginning capital plus 20% of the return, calculated independently. 12 − 1 − 0.20 × 12 = 8.6%.

On your calculator
  1. 12×0.8−1= 8.6
  1. 12ENTER0.8×1− 8.6

ENTER enter (on the HP, puts the number on the stack)

Investor return through a fund of funds Use it
ri=r1−m2−p2 r1r_i = r_1 - m_2 - p_2\,r_1
Quick example

The fund of funds receives 8.6% and charges 0.5% plus 5% of that return, calculated independently. 8.6 − 0.5 − 0.05 × 8.6 = 7.67%. Charge the second incentive fee on 8.6, not on the gross 12.

On your calculator
  1. 8.6×0.95−0.5= 7.67
  1. 8.6ENTER0.95×0.5− 7.67

ENTER enter (on the HP, puts the number on the stack)

Fund of funds fees on the combined value Use it
RFoF=V1 m2+max⁡[0,  (V1−V0) p2]R_{FoF} = V_1\,m_2 + \max\left[0,\; (V_1 - V_0)\,p_2\right]
Quick example

Invest 70 in total; the funds are worth 82.6 after their own fees. Fund of funds charges 1% of year-end value and 10% of the gain. Fees = 0.826 + 1.26 = 2.086, so the investor earns (12.6 − 2.086) ÷ 70 = 15.02%.

On your calculator
  1. 82.6×0.01=STO1 0.826
  2. 82.6−70=×0.1=STO2 1.26
  3. 82.6−70−RCL1−RCL2=÷70= 0.1502

STO store · RCL recall a stored number

  1. 82.6ENTER0.01×STO1 0.826
  2. 82.6ENTER70−0.1×STO2 1.26
  3. 82.6ENTER70−RCL1−RCL2−70÷ 0.1502

ENTER enter (on the HP, puts the number on the stack) · STO store · RCL recall a stored number

How it is asked

  1. Two-layer net return

    Underlying funds earn 13% gross and charge 2 and 20; a fund of funds charges 0.5 and 10 (all independent). Net?

    Layer 1: 13 − 2 − 2.6 = 8.4. Layer 2: 8.4 − 0.5 − 0.84 = 7.06%. Traps: 6.6% (second incentive fee on the gross 13) and 8.4% (stops after layer 1).

  2. Name the bias: failures disappear

    An index drops funds when they stop reporting after poor results. This is...

    Survivorship bias.

  3. Name the bias: history added

    A manager adds a fund to a database two years after launch, with its strong early returns. This is...

    Backfill bias. Trap: survivorship bias.

  4. Direction of bias

    Compared with all hedge funds that ever existed, an index with both biases reports returns that are...

    Higher.

Exam traps

  • Charging the fund of funds' incentive fee on the gross return instead of the net return it receives.
  • Saying survivorship bias understates returns. It overstates them.
  • Mixing backfill bias (adding good history) with survivorship bias (removing failures).
  • Stopping after the first layer of fees.

Checkpoint

6 exam-style questions. About 90 seconds each.

  1. 1Underlying hedge funds earn 18% gross and charge 1.5 and 20 (independent, management fee on beginning assets under management). A fund of funds charges 1 and 10 (independent) on the return it receives. The investor's net return is closest to:

  2. 2A hedge fund index that drops funds when they stop reporting after poor results suffers from:

  3. 3A manager adds a fund to a database two years after launch, including its strong early returns. This creates:

  4. 4A fund of funds invests CHF 60 million in one hedge fund and CHF 90 million in another. After the hedge funds' own fees, the holdings are worth CHF 54 million and CHF 111 million at year end. The fund of funds charges 0.75% of year-end value and a 10% incentive fee on the combined gain, calculated independently. The investor's net return is closest to:

  5. 5Compared with investing directly in a hedge fund, which of the following is least likely a benefit of a fund of funds?

  6. 6Compared with the average return of all hedge funds that ever existed, an index affected by both survivorship bias and backfill bias will most likely report returns that are:

Key takeaways

  • A fund of funds is two layers of fees, in return for selection, diversification and access.
  • Survivorship bias and backfill bias both overstate hedge fund index returns.
  • Compare like with like: same strategy, same vintage year, since inception.
Return after the hedge fund layer Use it
r1=r−m1−p1 rr_1 = r - m_1 - p_1\,r
Quick example

Hedge funds earn 12% gross and charge a 1% management fee on beginning capital plus 20% of the return, calculated independently. 12 − 1 − 0.20 × 12 = 8.6%.

On your calculator
  1. 12×0.8−1= 8.6
  1. 12ENTER0.8×1− 8.6

ENTER enter (on the HP, puts the number on the stack)

Investor return through a fund of funds Use it
ri=r1−m2−p2 r1r_i = r_1 - m_2 - p_2\,r_1
Quick example

The fund of funds receives 8.6% and charges 0.5% plus 5% of that return, calculated independently. 8.6 − 0.5 − 0.05 × 8.6 = 7.67%. Charge the second incentive fee on 8.6, not on the gross 12.

On your calculator
  1. 8.6×0.95−0.5= 7.67
  1. 8.6ENTER0.95×0.5− 7.67

ENTER enter (on the HP, puts the number on the stack)

Fund of funds fees on the combined value Use it
RFoF=V1 m2+max⁡[0,  (V1−V0) p2]R_{FoF} = V_1\,m_2 + \max\left[0,\; (V_1 - V_0)\,p_2\right]
Quick example

Invest 70 in total; the funds are worth 82.6 after their own fees. Fund of funds charges 1% of year-end value and 10% of the gain. Fees = 0.826 + 1.26 = 2.086, so the investor earns (12.6 − 2.086) ÷ 70 = 15.02%.

On your calculator
  1. 82.6×0.01=STO1 0.826
  2. 82.6−70=×0.1=STO2 1.26
  3. 82.6−70−RCL1−RCL2=÷70= 0.1502

STO store · RCL recall a stored number

  1. 82.6ENTER0.01×STO1 0.826
  2. 82.6ENTER70−0.1×STO2 1.26
  3. 82.6ENTER70−RCL1−RCL2−70÷ 0.1502

ENTER enter (on the HP, puts the number on the stack) · STO store · RCL recall a stored number

All Alternative Investments formulas, every lesson

Practice exam-style questions on Alternative Investment Performance and Returns

Questions about this lesson?

Where this comes back

Questions candidates ask

How do you calculate a fund of funds net return?

First net off the hedge funds' own fees to get the return the fund of funds receives. Then subtract the fund of funds' management fee and its incentive fee on that net return. With 15% gross, 2 and 20, then 1 and 10, the investor nets 10.0% and then 8.0%.

What is survivorship bias in hedge fund indexes?

It arises when funds that close, often after poor results, drop out of the database, leaving only survivors. The average return of the remaining funds is higher than the average of all funds that ever existed.

What is backfill bias?

It arises when a fund joins an index and its earlier returns are added, typically only for funds that did well. Adding that selective history raises the index's reported average return.

Spotted an error? Tell us and we will fix it.

  1. Why alternative investment performance is hard to judge
  2. IRR and multiple of invested capital (MOIC)
  3. Leverage, redemptions, lockups and gates
  4. Calculating returns after fees: management, incentive, hurdle and high-water mark
  5. Fund of funds fees, survivorship bias and backfill bias

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