How Mutual Funds Work Behind the Scenes: NAV, Units, and Fund Managers Explained

In our last post, we covered the basic idea of what a mutual fund actually is, a pool of money from many investors, managed professionally, invested collectively. If you have not read that one yet, it is worth starting there before this post, since everything here builds directly on that foundation. This time, we are going one level deeper on Mutual Funds. Once you understand what mutual funds are, the natural next question is how it actually works on a day to day basis. What happens when you invest money. How is your share of the fund calculated. Who is actually making the decisions with your money, and how are they held accountable.

I think this is the part where a lot of beginners quietly disengage, because terms like NAV and AUM get thrown around without much explanation, as if everyone is already supposed to know what they mean. So let us slow down and go through each piece properly, because once you understand these mechanics, mutual funds statements and fact sheets stop looking like a foreign language.

Net Asset Value: The Number That Decides Everything

Net Asset Value, almost always shortened to NAV, is simply the price of one unit of a mutual fund on any given day. It is calculated by taking the total value of everything the fund owns, all its stocks, bonds, or other holdings, subtracting any liabilities or expenses, and dividing that number by the total number of units currently held by all investors in the fund.

This calculation happens once every business day, after the markets close, which is why mutual funds transactions do not happen at a live, constantly changing price the way stock trading does. When you invest money into a mutual funds, you are allotted units based on that day’s NAV. If the NAV is one hundred rupees and you invest one thousand rupees, you receive ten units of the fund, ignoring any transaction charges for simplicity.

Why a Lower NAV Does Not Mean a Fund Is Cheaper or Better

This is one of the most common misunderstandings among beginners, and it is worth addressing directly. A fund with a NAV of ten rupees is not inherently cheaper or a better deal than a fund with a NAV of five hundred rupees. What actually matters is the percentage growth in NAV over time, not the absolute starting number.

Think of it like comparing pizza slices cut into different numbers of pieces. A pizza cut into four large slices and a pizza cut into eight small slices contain the same total amount of pizza, the slice count just determines how many pieces you get. Similarly, NAV simply determines how many units you receive for your investment amount, but your total investment value and its future growth depend on the percentage change in NAV, not its starting price.

Units: Your Actual Ownership Stake in the Fund

Every time you invest in a mutual fund, whether through a lump sum or a systematic investment plan, you are allotted a certain number of units based on the prevailing NAV on that transaction date. Over time, as you continue investing, particularly through a SIP, you accumulate more units at different NAVs, since the NAV fluctuates from month to month based on market performance.

Your total investment value at any point is simply the total number of units you own multiplied by the current NAV. This is why your account statement typically shows both your unit balance and the current NAV, since together they determine exactly how much your investment is worth on that day.

Assets Under Management: The Size of the Pool

Assets Under Management, commonly abbreviated as AUM, refers to the total market value of all the investments a particular mutual fund scheme holds at a given point in time. This number reflects the combined money of every investor in that fund, and it changes constantly as new investors join, existing investors redeem their units, and the value of the fund’s underlying holdings rises or falls with the market.

A larger AUM generally indicates that a fund has attracted significant investor confidence and has been operating for a meaningful period, though a bigger AUM does not automatically mean a fund is a better choice. Extremely large funds can sometimes face challenges finding enough attractive investment opportunities to deploy all their capital effectively, particularly in more niche fund categories.

The Fund Manager: Who Is Actually Making the Decisions

Every mutual fund scheme has a designated fund manager, or sometimes a team of managers, responsible for making the actual investment decisions within the boundaries of the fund’s stated objective and category. Their job includes researching potential investments, deciding when to buy or sell specific holdings, and continuously managing the fund’s overall risk and return profile.

Fund managers do not operate with complete freedom. Every scheme has a clearly defined mandate, disclosed in its offer document, which dictates the type of securities the fund is allowed to invest in, and regulatory guidelines further restrict how concentrated or risky a fund’s holdings can become. This structure exists specifically to protect investors from a fund manager taking on excessive or undisclosed risk with pooled investor money.

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The Asset Management Company: The Organization Behind the Fund

The fund manager works within a larger organization called an Asset Management Company, commonly referred to as an AMC. The AMC is the entity that actually launches and operates various mutual fund schemes, employs fund managers and research analysts, and is responsible for the overall governance and compliance of every fund it offers.

When people refer to a mutual fund by a brand name, they are really referring to a specific scheme offered by that AMC. A single AMC typically offers dozens of different fund schemes across categories like equity, debt, and hybrid funds, each with its own fund manager, objective, and NAV.

How Regulation Protects Investors in This Entire Process

Mutual funds operate under strict oversight from the country’s securities market regulator, which sets rules around everything from how NAV must be calculated and disclosed, to how much a fund can invest in a single company, to what information must be disclosed to investors on a regular basis. AMCs are required to publish detailed fact sheets, portfolio holdings, and performance data at regular intervals, giving investors the ability to see exactly what their money is invested in.

This regulatory structure is a meaningful part of why mutual funds are considered a relatively transparent investment vehicle compared to unregulated investment schemes, since there are clear rules governing disclosure, fund manager conduct, and investor protection throughout the entire process.

Putting It All Together With a Simple Walkthrough

Step	What Happens
You invest money	Your amount is used to purchase units at that day’s NAV
The fund pools your money	Combined with money from thousands of other investors
The fund manager invests the pool	Buys stocks, bonds, or other assets per the fund’s mandate
NAV is calculated daily	Reflects the current value of the fund’s total holdings per unit
Your investment value changes	Equals your total units multiplied by the current NAV
You redeem your investment	You receive the current value of your units, based on that day’s NAV

A Personal Note on This One

Once these mechanics clicked for me, mutual fund statements stopped feeling intimidating and started feeling like something I could actually read and understand. I think the biggest shift is realizing that a mutual fund is not some abstract black box, it is a fairly logical system with clear rules, regular disclosures, and a straightforward math behind how your investment value is calculated every single day. Understanding this does not require a finance degree, it just requires someone to walk you through it once, properly.

Frequently Asked Questions

Does a higher NAV mean a mutual fund is more expensive to invest in?

Not really. A higher NAV simply means each unit costs more, so you receive fewer units for the same investment amount. What actually matters for your returns is the percentage growth in NAV over time, not its absolute value.

How often does a mutual fund’s NAV change?

NAV is typically calculated and updated once every business day after markets close, based on the closing value of the fund’s underlying holdings.

Can a fund manager invest in anything they want?

No. Every fund operates under a specific mandate disclosed in its offer document, and regulatory guidelines restrict how a fund manager can allocate the pooled money, including limits on concentration in any single company or sector.

What happens to my investment if the fund manager changes?

Fund manager changes are disclosed to investors and do not affect your existing units or their value. The new manager continues operating the fund within the same stated mandate and objective, though investment style may shift somewhat depending on the new manager’s approach.

Is a bigger fund, meaning higher AUM, always a better choice?

Not necessarily. While a large AUM can reflect investor confidence, it does not guarantee better performance, and in some cases very large funds in niche categories can face challenges finding enough opportunities to deploy their capital effectively.

Where can I check a mutual fund’s current NAV and holdings?

NAV and portfolio holdings are typically published on the Asset Management Company’s official website and on regulatory or industry association websites that track mutual fund data, usually updated daily or monthly depending on the specific information.

About This Guide

This is the second post in our ongoing mutual fund series, building directly on our introductory guide covering the basics of what a mutual fund is. This piece focuses specifically on the operational mechanics behind mutual funds, drawing on publicly available regulatory disclosures and standard industry practices to keep the explanations accurate and grounded for everyday readers.

Disclaimer

This article is intended for general informational and educational purposes only and does not constitute financial or investment advice. Mutual fund investments are subject to market risk, and NAV can fluctuate based on market conditions, meaning the value of your investment is not guaranteed. Before making any investment decisions, please read all scheme related documents carefully and consult a qualified and registered financial advisor who can assess your individual financial situation, goals, and risk tolerance. The author and publisher of this content are not liable for any financial decisions made based on the information provided in this article.