The Alpha Claim with Style Drift
A client holds a large-cap index fund and shows you a fact sheet for Bharat Growth Fund. Over three years, Bharat Growth's CAGR is 22.1% and the Nifty 500 TRI returned 18.4%. The fact sheet calls this consistent alpha. The fund now has 55% in small- and mid-caps, portfolio turnover of 180%, an expense ratio of 1.85% and annualised standard deviation of 24.5%. The benchmark's standard deviation is 16.2%. The risk-free rate is 6.5%. The client wants to switch his entire ₹30 lakh retirement portfolio into Bharat Growth because the fund beats the index by 3.7%. The fund's manager changed 14 months ago, and the current portfolio is concentrated in 28 stocks. The client's horizon is 12 years and he draws no income from this portfolio.
1. Calculate and interpret the Sharpe ratios. Does the fund's return establish superior risk-adjusted performance?
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Sharpe ratio = (portfolio return minus risk-free rate) divided by standard deviation. For Bharat Growth: (22.1 - 6.5) / 24.5 = 15.6 / 24.5 = 0.637. For the Nifty 500: (18.4 - 6.5) / 16.2 = 11.9 / 16.2 = 0.735. The fund generated a higher raw return but a lower Sharpe ratio, so it did not deliver better risk-adjusted performance over this period. The comparison also flatters the fund because its current portfolio is 55% small- and mid-cap while the benchmark is broader; the fund has taken style risk not captured by the Nifty 500 comparison. A 24.5% standard deviation means much wider drawdowns. The 180% turnover and 1.85% expense ratio create implementation drag that the gross return may not reflect. The 3.7% alpha is therefore not established as skill. It may be compensation for style exposure, concentration and manager change risk.
2. How should you present the switch decision, and what further analysis is needed before any recommendation?
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Present the raw return and the risk-adjusted return side by side. Explain that 22.1% versus 18.4% is not a like-for-like alpha if the fund has migrated to small- and mid-caps. Compare against a blended or appropriate style benchmark, and review rolling three-year returns, downside capture, drawdowns and performance before and after the manager change. Check whether the 1.85% expense ratio is the direct or regular plan, and quantify the cost drag over 12 years. Assess concentration in 28 stocks and liquidity in the small- and mid-cap segment. Consider tax on selling the existing index fund and the client's ability to tolerate a 24.5% standard deviation. A reasonable outcome may be a core-satellite structure, keeping the index fund as the core and adding a limited satellite only if the client understands the style risk. Document the analysis and the client's decision; do not recommend an all-in switch based on one fact-sheet period.