The mechanics are simple. An index fund buys every stock in the underlying index in the same weight. When the index rebalances, the fund rebalances too.
The Nifty Midcap 150 is the most common benchmark. It covers companies ranked 101 to 250 by full market capitalisation within the Nifty 500 . The index uses a free-float market capitalisation method, meaning only shares available for public trading count toward the weight .
Inclusion criteria are strict. A company must be part of the Nifty 500. It gets excluded if its rank falls below 275 or if it drops out of the Nifty 500 . The index rebalances twice a year, in January and July .
Several fund houses offer Nifty Midcap 150 index funds. Motilal Oswal, Aditya Birla Sun Life, Nippon India, Kotak, and DSP are among the prominent names . Expense ratios for direct plans range from about 0.33% to 0.63% .
why the index is hard to beat
The case for passive midcap investing rests on a single data point: very few active managers beat the index consistently.
A 15-year study by Value Research found that out of 24 midcap funds old enough for analysis, only five beat the Nifty Midcap 150 TRI in at least 60% of rolling five-year periods. Only nine beat it more than half the time .
A separate analysis by freefincal looked at 21 direct plan midcap funds with at least five years of history. Over five-year rolling periods, only four funds qualified with an outperformance consistency of 70% or more .
The pattern holds across time frames. Over four years, four out of 22 funds qualified. Over three years, five out of 27 .
That does not mean active midcap funds never outperform. It means the outperformance is inconsistent and hard to identify in advance.
what the returns look like
The Nifty Midcap 150 has delivered strong returns over recent periods. Three-year returns stood at 22.2%. Five-year returns were 17.8% .
Individual index funds track this closely. Nippon India Nifty Midcap 150 Index Fund showed a 3-year CAGR of 16.22% and a 5-year CAGR of 16.59% as of April 2026. Motilal Oswal’s version showed 16.46% and 16.81% respectively .
The higher figures in some sources reflect different time periods. The 22.2% three-year return for the index covers a period when midcaps outperformed. A five-year view captures a longer cycle and settles closer to 17-18% .
the liquidity question
There is one unresolved risk in the midcap index fund story.
Freefincal’s analysis raised a concern that has not yet been tested. No abrupt crash has occurred in the Nifty Midcap 150 that caused liquidity to evaporate suddenly. If that happens, the question is how a fund manager copes, especially when the fund’s assets under management have grown large .
Midcap stocks trade less liquidly than largecaps. In a sharp downturn, selling pressure can be harder to absorb. That risk sits in the background even when returns look strong.
who should consider a midcap index fund
Investors who want midcap exposure without manager risk. The index fund removes the decision of which active manager to pick. That decision is difficult because past performance does not reliably predict future outperformance .
Investors building a Nifty 50 plus midcap combination. A Nifty 50 index fund paired with a Nifty Midcap 150 index fund gives largecap stability alongside midcap growth potential. Freefincal described this as “certainly not a terrible idea” .
Investors comfortable with higher volatility. Midcaps are more volatile than largecaps. The index can underperform for extended periods, as it did in earlier cycles .
Investors with a long time horizon. The volatility makes short-term investing unsuitable. A 7 to 10 year horizon allows market cycles to play out.
what to watch before investing
Tracking error. This measures how closely the fund follows its index. Lower is better. Nippon India’s fund showed a tracking error of 0.15% and Motilal Oswal’s 0.06% as of April 2026 .
Expense ratio. Direct plans are cheaper than regular plans. The difference compounds over years. Motilal Oswal charges 0.33% in direct plan; Aditya Birla charges 0.44% .
AUM size. Smaller funds may face liquidity constraints when they grow. Kotak’s Nifty Midcap 150 Index Fund had ₹25 crore AUM as of March 2026, which is small .
Exit load. Most index funds have no exit load, but check the scheme documents.
Taxation. Equity mutual funds held for more than 12 months attract long-term capital gains tax at 12.5% above ₹1.25 lakh. Short-term gains are taxed at 20% .
Frequently Asked Questions
1. What is a midcap index fund?
An index fund that tracks a midcap benchmark like the Nifty Midcap 150. It buys all stocks in the index in the same weight, aiming to match the index return before expenses. It does not try to beat the market.
2. How is the Nifty Midcap 150 constructed?
It represents companies ranked 101 to 250 by market capitalisation within the Nifty 500. The index uses free-float market capitalisation and rebalances semi-annually in January and July .
3. Do midcap index funds beat active midcap funds?
Not always, but consistency is rare in active funds. A 15-year study found only five out of 24 active midcap funds beat the Nifty Midcap 150 in at least 60% of rolling five-year periods .
4. What returns have midcap index funds delivered?
The Nifty Midcap 150 delivered 22.2% over three years and 17.8% over five years as of April 2026 . Individual index funds track close to this, with 5-year CAGRs around 16.5% .
5. What is the biggest risk in midcap index funds?
Liquidity. Midcap stocks trade less liquidly than largecaps. If a sharp crash causes liquidity to evaporate, selling pressure could be harder to absorb, especially for funds with large AUM .
