- Why Past Returns Aren't Enough
- The 8 Ratios You Need to Know
- Quick Reference: What to Look For
- Things to Keep in Mind
- The Bottom Line
Most investors pick mutual funds based on past returns or star ratings, but neither tells you how risky the fund actually is today. With over 1,000 mutual fund schemes available in India, choosing the right one requires more than just a return chart.
Here are 8 ratios that give you a complete picture.
Why Past Returns Aren't Enough
A fund that returned 40% last year could have a Beta of 2, meaning it also falls twice as hard when markets drop. Star ratings can change over time. NAV is just a price, not a quality indicator. Ratios tell you how a fund is generating returns, and at what risk and cost.
The 8 Ratios You Need to Know
1. Expense Ratio: What It Costs You to Stay Invested
Every mutual fund charges an annual fee to cover salaries, fund manager fees, research, and operations. This is the expense ratio; it is not charged to you as a separate bill. Instead, it is deducted directly from the fund's assets and reflected in your NAV and returns every single day.
The formula:
Expense Ratio = Total Annual Fund Expenses ÷ Average Assets Under Management × 100
Actively managed funds typically charge between 1–2.5%, while index funds charge as low as 0.1–0.5% since they simply replicate an index without needing a large research team.
Simple example: Suppose you invest ₹1,00,000 in two funds that both generate a gross return of 12% per year over 20 years.
- Fund A (Active) has an expense ratio of 1.5% → Net return = 10.5%
- Fund B (Index) has an expense ratio of 0.5% → Net return = 11.5%
| Fund A (1.5% expense) | Fund B (0.5% expense) | |
| Investment | ₹1,00,000 | ₹1,00,000 |
| Net Annual Return | 10.5% | 11.5% |
| Value after 20 years | ₹7.32 lakh | ₹8.86 lakh |
A 1% difference in expense ratio costs you over ₹1.5 lakh on a ₹1 lakh investment over 20 years, without any difference in the fund's gross performance.
What to look for: Always compare expense ratios within the same category. A 1.5% expense ratio is acceptable for an active small-cap fund, but hard to justify for a large-cap fund where index alternatives exist at a fraction of the cost.
2. Standard Deviation: How Volatile Is the Fund?
Standard deviation measures how much a fund's returns fluctuate around its average. A higher number means more volatility, larger gains when markets rise, and larger losses when they fall.
For example, if a large-cap fund has a standard deviation of 18% and a small-cap fund has 26%, both may show similar 3-year returns, but the small-cap fund's journey was far more volatile to get there.
What to look for: Match this to your risk tolerance. If market swings make you uncomfortable, choose funds with a lower standard deviation.
3. Sharpe Ratio: Are You Being Paid for the Risk?
The Sharpe ratio measures how much return a fund generates for every unit of risk it takes. Think of it as a value-for-risk check, not just what a fund returned, but how much risk it took to get there.
The formula:
Sharpe Ratio = (Fund Return − Risk-Free Rate) ÷ Standard Deviation
The risk-free rate is typically the return on a government bond, currently around ~7% in India.
Simple example: Suppose two small-cap funds both returned 15% over the past 3 years.
- Fund A has a standard deviation of 12% → Sharpe = (15 − 7) ÷ 12 = 0.67
- Fund B has a standard deviation of 8% → Sharpe = (15 − 7) ÷ 8 = 1.0
Both funds gave you the same return, but Fund B delivered it with significantly less volatility. Fund B is the better risk-adjusted bet.
What to look for: A Sharpe ratio of 1 or above is generally considered good. Always compare within the same fund category; don't use it to compare a small-cap fund with a debt fund.
4. Treynor Ratio: A Smarter Measure for Diversified Portfolios
The Treynor ratio is similar to the Sharpe ratio, but with one key difference: instead of using total volatility (standard deviation), it uses Beta, which only accounts for market risk.
This makes it more relevant for investors holding a diversified portfolio, where fund-specific risks are already reduced. The higher the Treynor ratio, the better the return generated per unit of market risk taken.
What to look for: Use Treynor when comparing diversified funds against each other. Use Sharpe when evaluating a fund in isolation.
5. Beta: How Much Does the Fund Move With the Market?
Beta measures how sensitive a fund is to market movements relative to its benchmark.
If a fund has a Beta of 2 and the Nifty rises 3%, the fund rises 6%. But if the Nifty falls 2%, the fund falls 4%. A Beta of 1 means the fund moves in line with the market. Above 1 means more volatile, below 1 means less volatile.
What to look for: A Beta of 1 or below is generally safer. If a fund carries a Beta above 1, check whether the higher volatility is justified by its Alpha.
6. Alpha: Is the Fund Manager Actually Adding Value?
Alpha measures the excess return a fund generates over and above what its risk level should theoretically produce.
Simple example: If the benchmark returns 10% and the fund's Beta is 1.4, the expected return is 14% (10% × 1.4). If the fund actually returned 15%, the Alpha is +1%. If it returned 13%, the Alpha is -1%, and the fund underperformed even after accounting for the risk it took on.
What to look for: Positive Alpha over a long period means the fund manager is genuinely adding value. Consistent negative Alpha in an actively managed fund is a red flag.
7. Sortino Ratio: Does the Fund Protect You When Markets Fall?
The Sortino ratio works like the Sharpe ratio, but with one important difference: it only measures downside volatility, ignoring upside swings entirely.
The Sharpe ratio penalises a fund for being volatile even when that volatility is on the upside. The Sortino ratio focuses only on the volatility that actually hurts when markets are falling.
What to look for: A higher Sortino ratio means the fund delivers better returns relative to its downside risk. Particularly useful for conservative investors who prioritise capital protection.
8. Turnover Ratio: How Actively Is the Fund Manager Trading?
The turnover ratio measures how frequently a fund's holdings are replaced within a year. A 0% ratio means no holdings were changed. A 100% ratio means the entire portfolio was replaced.
Index funds usually have lower turnover than actively managed funds, though the exact level depends on the index and rebalancing rules. Higher turnover is not automatically bad, but it can lead to higher transaction costs and, in taxable accounts, higher tax impact.
What to look for: If an active fund's turnover ratio is 60–70% or higher compared to peers in the same category, investigate why. High turnover is not inherently bad, but it needs to be justified by returns.
Quick Reference: What to Look For
| Ratio | What It Measures | Ideal Value |
| Expense Ratio | Annual cost of running the fund | Lower the better |
| Standard Deviation | Volatility of returns | Lower = less risky |
| Sharpe Ratio | Return per unit of total risk | 1 or higher |
| Treynor Ratio | Return per unit of market risk | The higher the better |
| Beta | Sensitivity to market movements | 1 or below |
| Alpha | Fund manager's value-add | Positive |
| Sortino Ratio | Return vs. downside risk only | The higher the better |
| Turnover Ratio | Frequency of portfolio trading | Lower = fewer hidden costs |
Things to Keep in Mind
- Use these ratios together, not in isolation. A high Sharpe ratio paired with a high expense ratio and high turnover can still quietly erode returns over time.
- Always compare within the same category. A Beta of 1.2 in a small-cap fund is very different from a Beta of 1.2 in a large-cap fund; context matters.
- All ratios are backwards-looking. They reflect historical data. Strong past ratios do not guarantee future performance.
- High turnover + high expense ratio is a double cost warning. Both eat into returns simultaneously and are worth flagging before investing.
- Low Beta does not mean low returns. Some conservative, low-Beta funds have consistently delivered positive Alpha over long periods.
The Bottom Line
Ratios don't guarantee returns, but they give you a far more complete picture of risk, cost, and fund quality than star ratings or past performance ever will. Use them as a filter before investing, not as the final word.
One cautious note: a fund that scores well on all eight ratios may still not suit your specific financial goal or investment timeline. Always map these numbers to your own situation before making a decision.
Disclaimer: The content is meant for education and general information purposes only. Past performance is not indicative of future returns. Mutual Funds are non-exchange traded products, and INDstocks is merely acting as a mutual fund distributor. All disputes with respect to distribution activity, would not have access to the exchange investor redressal forum or arbitration mechanism. Mutual Fund investments are subject to market risks, read all scheme related documents carefully before investing. INDstocks Private Limited (formerly known as INDmoney Private Limited) 616, Level 6, Suncity Success Tower, Sector 65, Gurugram, 122005, SEBI Stock Broking Registration No: INZ000305337, Trading and Clearing Member of NSE (90267, M70042) and BSE, BSE StarMF (6779), AMFI Registration No: ARN-254564, SEBI Depository Participant Reg. No. IN-DP-690-2022, Depository Participant ID: CDSL 12095500, Research Analyst Registration No. INH000018948 BSE RA Enlistment No. 6428.