Level 5 — MasteryFunds, ETFs & Pooled Vehicles

Funds, ETFs & Pooled Vehicles

90 minutes60 marksprintable — key stays hidden on paper

Level: 5 (Mastery — cross-domain: finance math, modelling, coding, proof) Time Limit: 90 minutes Total Marks: 60


Instructions

Answer all three questions. Show full derivations. Where code is requested, provide clean, runnable Python (NumPy allowed). Justify every modelling assumption.


Question 1 — NAV, Expense Ratios & Tracking Error (20 marks)

An index fund tracks a benchmark. On day 0 the fund's assets are ₹500,000,000 with 25,000,000 units outstanding, and there are no liabilities.

(a) Compute the day-0 NAV per unit. (2)

(b) The fund charges a Total Expense Ratio (TER) of e=0.20%e = 0.20\% per annum, deducted daily on a 365-day convention. Prove that if the fund's gross assets grow at a continuously-compounded gross return rgr_g over one year, then the net (after-fee) growth factor of NAV per unit is approximately erg(1e)e^{r_g}(1 - e), and state precisely the approximation you make. (5)

(c) Over one year the benchmark returned Rb=12.00%R_b = 12.00\% (simple annual). The fund reported a net return of Rf=11.60%R_f = 11.60\%. Decompose the 0.40%0.40\% shortfall into the portion explained by the TER and the residual "structural" tracking drag. Then define tracking error properly and explain why the single-year shortfall you computed is not itself the tracking error. (6)

(d) Two funds track the same index. Fund A: TER 0.05%0.05\%, annualised tracking error (std. dev. of daily active returns, annualised) =0.15%= 0.15\%. Fund B: TER 0.35%0.35\%, tracking error =0.04%= 0.04\%. A pension trustee must pick one for a 20-year buy-and-hold mandate. Argue quantitatively which fund is preferable and identify the single most important factor for this horizon. (7)


Question 2 — SIP vs Lumpsum: Build & Prove (22 marks)

Consider monthly investing over nn months. Let unit price at month ii (start of month, i=0,,n1i=0,\dots,n-1) be pip_i.

(a) A SIP invests a fixed rupee amount AA each month. Prove that the average cost per unit acquired by the SIP is the harmonic mean of the prices p0,,pn1p_0,\dots,p_{n-1}, and that this is always \le the arithmetic mean. State the inequality's name and the equality condition. (8)

(b) Write a Python function sip_vs_lumpsum(prices, monthly_amount) that returns a dict with: SIP final value, lumpsum final value (whole SIP budget invested at p0p_0), and the outperformance of SIP over lumpsum in rupees, all valued at the final price pn1p_{n-1}. (6)

(c) Using the price path prices = [100, 90, 80, 100, 120] and monthly_amount = 12000, compute by hand (or trace the code) both final values and state which strategy wins and by how much. (5)

(d) Prove the general condition on the price path under which lumpsum beats SIP. State it as a clean inequality relating p0p_0 to the harmonic mean, and give the finance intuition. (3)


Question 3 — Pooled Vehicle Structures & Taxation Modelling (18 marks)

(a) A REIT is required to distribute at least 90% of its net distributable cash flow. Contrast the return mechanics of a Gold ETF, an equity index ETF, and a REIT for an investor: for each, identify the primary source(s) of investor return and one structural risk unique to it. (6)

(b) An ELSS fund and a non-ELSS equity fund both return 12%12\% p.a. compounded. An investor puts in ₹150,000 today. The ELSS has a mandatory 3-year lock-in; the other has an exit load of 1%1\% if redeemed within 1 year, then 0%0\%. Assuming redemption at year 3 for both, and ignoring capital-gains tax, compute the year-3 value of each and explain why "lock-in" and "exit load" are different liquidity mechanisms. (6)

(c) A Fund of Funds (FoF) invests in underlying funds each charging TER 0.60%0.60\%, and the FoF itself charges 0.40%0.40\%. Derive the investor's effective total annual expense drag, prove it is (to first order) additive, and state the second-order correction term. Comment on why a closed-end fund trading at a discount to NAV can partially offset expense drag for a buyer. (6)


End of paper.

Answer keyMark scheme & solutions

Question 1

(a) NAV = (Assets − Liabilities)/Units = 500,000,000/25,000,000=20.00500{,}000{,}000 / 25{,}000{,}000 = ₹20.00. (2 marks: 1 formula, 1 value)

(b) Daily fee fraction =e/365= e/365. Over 365 days, net multiplier from fees alone =(1e/365)365= (1 - e/365)^{365}. Gross growth over the year (continuous) =erg= e^{r_g}. Net NAV growth =erg(1e/365)365= e^{r_g}\,(1 - e/365)^{365}. Now (1e/365)365ee(1 - e/365)^{365} \to e^{-e} as the daily deduction is compounded; and for small ee, ee1e+e22e^{-e} \approx 1 - e + \tfrac{e^2}{2}, so to first order (1e/365)3651e(1-e/365)^{365}\approx 1-e. Hence net growth erg(1e)\approx e^{r_g}(1-e). Approximation stated: dropping the O(e2)O(e^2) term (fee-on-fee compounding), valid because e=0.0021e=0.002\ll1. (5 marks: 2 set-up multipliers, 2 limit/expansion, 1 explicit approximation statement)

(c) Total shortfall =RbRf=12.00%11.60%=0.40%= R_b - R_f = 12.00\% - 11.60\% = 0.40\%.

  • TER portion =0.20%= 0.20\%.
  • Structural drag (residual) =0.40%0.20%=0.20%= 0.40\% - 0.20\% = 0.20\% (cash drag, rebalancing/transaction costs, sampling error, dividend timing).

Tracking error definition: the standard deviation of the fund's active return (fund return minus benchmark return) measured over many periods — a dispersion/volatility measure, not a level. The single-year shortfall of 0.40%0.40\% is a realised mean active return (tracking difference), one draw; tracking error requires the variability across a series of active returns. (6 marks: 2 TER/residual split, 2 numeric, 2 definition + distinction)

(d) Over 20 years the dominant, persistent, compounding drag is TER. Expected cumulative cost difference in TER =(0.35%0.05%)=0.30%= (0.35\% - 0.05\%) = 0.30\%/yr 0.30%×20=6%\approx 0.30\% \times 20 = 6\% compounded ≈ a value drag of roughly 1(10.003)205.83%1-(1-0.003)^{20}\approx 5.83\% of terminal wealth in favour of Fund A. Tracking error is a dispersion term that does not accumulate as a directional cost and largely averages out over long horizons; the 0.15%0.15\% vs 0.04%0.04\% difference is second-order for a buy-and-hold trustee who does not trade on short-term deviations. Choose Fund A. Most important factor for a 20-year buy-and-hold: the expense ratio (TER), because it is a guaranteed recurring compounding cost. (7 marks: 3 quantitative TER argument, 2 tracking-error-averages-out argument, 2 decision + factor)


Question 2

(a) SIP buys A/piA/p_i units in month ii.

  • Total units U=i=0n1A/pi=A1/piU = \sum_{i=0}^{n-1} A/p_i = A\sum 1/p_i.
  • Total invested =nA= nA.
  • Average cost cˉ=nAA1/pi=ni=0n11/pi=H\bar c = \dfrac{nA}{A\sum 1/p_i} = \dfrac{n}{\sum_{i=0}^{n-1} 1/p_i} = H, the harmonic mean of the prices.

By the AM–HM inequality, HAM=1npiH \le \text{AM} = \frac{1}{n}\sum p_i, with equality iff all pip_i are equal. Proof of inequality (AM–HM): By Cauchy–Schwarz, (pi)(1/pi)n2\left(\sum p_i\right)\left(\sum 1/p_i\right)\ge n^2, so pinn1/pi\frac{\sum p_i}{n}\ge \frac{n}{\sum 1/p_i}, i.e. AM ≥ HM. Equality when pip_i constant. Name: Arithmetic Mean–Harmonic Mean inequality. (8 marks: 2 units expression, 2 harmonic-mean identity, 3 AM–HM proof, 1 equality condition)

(b)

def sip_vs_lumpsum(prices, monthly_amount):
    n = len(prices)
    units_sip = sum(monthly_amount / p for p in prices)
    final_p = prices[-1]
    sip_value = units_sip * final_p
    budget = monthly_amount * n
    units_lump = budget / prices[0]
    lump_value = units_lump * final_p
    return {
        "sip_value": sip_value,
        "lumpsum_value": lump_value,
        "sip_outperformance": sip_value - lump_value,
    }

(6 marks: 2 SIP units/value, 2 lumpsum, 2 dict/return correctness)

(c) prices = [100,90,80,100,120], A = 12000, n=5, budget = 60000, final price 120. SIP units: 120+133.3+150+120+100=623.333120 + 133.\overline{3} + 150 + 120 + 100 = 623.333\ldots

  • month0: 12000/100 = 120
  • month1: 12000/90 = 133.3333
  • month2: 12000/80 = 150
  • month3: 12000/100 = 120
  • month4: 12000/120 = 100 Total = 623.3333 units. SIP value = 623.3333×120=74,800623.3333 \times 120 = ₹74{,}800. Lumpsum: 60000/100 = 600 units → value 600×120=72,000600 \times 120 = ₹72{,}000. SIP wins by ₹2,800. (Because average buy price via harmonic mean was below the lumpsum's single price 100 given the dip.) (5 marks: 3 SIP value, 1 lumpsum, 1 verdict + margin)

(d) Lumpsum invests all budget nAnA at p0p_0, acquiring nA/p0nA/p_0 units; SIP acquires A1/pi=nA/HA\sum 1/p_i = nA/H units where HH is the harmonic mean. Both valued at pn1p_{n-1}, so lumpsum beats SIP iff it holds more units: nAp0>nAH    p0<H.\frac{nA}{p_0} > \frac{nA}{H} \iff p_0 < H. Condition: p0<Hp_0 < H (entry price below the harmonic mean of the price path). Intuition: if you enter cheaply relative to the average subsequent purchase cost — i.e. prices generally rose after entry — deploying capital immediately captures more of the rise, so lumpsum wins. (3 marks: 2 inequality derivation, 1 intuition)


Question 3

(a) (6 marks: 1 return source + 1 unique risk each)

  • Gold ETF: return solely from gold price movement (no yield/coupon/dividend); unique risk = commodity price risk / no income, plus small physical-gold custody & tracking cost.
  • Equity index ETF: return from constituent price appreciation + dividends passed through; unique risk = full equity/market systematic risk, tracking error from rebalancing.
  • REIT: return from mandatory distributions (rental income, ≥90% payout) + capital appreciation of units; unique risk = property/interest-rate sensitivity and distribution cuts if occupancy/rents fall.

(b) Year-3 values, both at 12% compounded:

  • ELSS: 150000×1.123=150000×1.404928=210,739.20150000 \times 1.12^3 = 150000 \times 1.404928 = ₹210{,}739.20. Exit load N/A (past lock-in); lock-in already expired at year 3, so full value received.
  • Non-ELSS: redeemed at year 3, exit load only applies within 1 year, so 0% load at year 3 → also 150000×1.123=210,739.20150000\times1.12^3 = ₹210{,}739.20. Both = ₹210,739.20 at year 3 (ignoring taxes). Distinction: Lock-in = hard prohibition on redemption (you legally cannot exit for 3 years). Exit load = soft penalty (you may exit anytime but pay a fee within the window). ELSS constrains liquidity absolutely; exit load merely prices early liquidity. (6 marks: 2 each value, 2 lock-in vs load distinction)

(c) FoF investor bears both layers. Net-of-fee wealth factor over a year with gross growth factor gg: W=g(1eunder)(1efof).W = g\,(1 - e_{under})(1 - e_{fof}). Effective drag EE satisfies (1E)=(1eunder)(1efof)=1eunderefof+eunderefof(1-E) = (1-e_{under})(1-e_{fof}) = 1 - e_{under} - e_{fof} + e_{under}e_{fof}. E=eunder+efofeunderefof.E = e_{under}+e_{fof} - e_{under}e_{fof}.

  • First-order (additive): Eeunder+efof=0.60%+0.40%=1.00%E \approx e_{under}+e_{fof} = 0.60\% + 0.40\% = 1.00\%.
  • Second-order correction: eunderefof=0.006×0.004=0.000024=0.0024%-e_{under}e_{fof} = -0.006\times0.004 = -0.000024 = -0.0024\%, so exact E=0.9976%E = 0.9976\%. Closed-end discount: a buyer purchasing units at, say, 10% below NAV gets exposure to full-NAV assets for 90% of the price; the extra NAV per rupee invested raises effective yield and can offset the expense drag (and if the discount narrows, provides additional return). (6 marks: 2 derivation of (1E)(1-E) product, 2 additive first-order + second-order term, 2 closed-end discount reasoning)

[
  {"claim":"Day-0 NAV = 20", "code":"assets=500000000; units=25000000; result = (assets/units == 20)"},
  {"claim":"(1-e/365)**365 approx 1-e for e=0.002", "code":"e=0.002; approx=(1-e/365)**365; result = abs(approx-(1-e))<1e-5"},
  {"claim":"SIP value = 74800 for given path", "code":"prices=[100,90,80,100,120]; A=12000; u=sum(A/p for p in prices); result = abs(u*prices[-1]-74800)<1e-6"},
  {"claim":"Lumpsum value = 72000 and SIP outperforms by 2800", "code":"prices=[100,90,80,100,120]; A=12000; n=len(prices); u=sum(A/p for p in prices); sipv=u*prices[-1]; lumpv=(A*n/prices[0])*prices[-1]; result = (abs(lumpv-72000)<1e-6) and (abs(sipv-lumpv-2800)<1e-6)"},
  {"claim":"ELSS year-3 value = 210739.20", "code":"v=150000*(1.12**3); result = abs(v-210739.2)<1e-2"},
  {"claim":"FoF effective drag = 0.9976%", "code":"eu=0.006; ef=0.004; E=eu+ef-eu*ef; result = abs(E-0.009976)<1e-9"}
]