Mutual Fund Comparison: Share Classes, Real Cost and What the Holdings Show

Mutual fund comparison goes wrong in a specific and repeatable place. Two funds show different long run returns, the gap gets read as a difference in management, and quite often the two lines are the same portfolio sold under two share classes at two different prices. American Funds Growth Fund of America is one portfolio, and its A class and its R-6 class compounded 0.38 percentage points apart every year for ten years. Nothing about the stocks differed. Only the price of access did.

The opposite error is just as common. Five funds sit inside one category label, look interchangeable on a summary page, and behave nothing alike: over the five years to August 14, 2026 the large growth funds below finished 7.58 percentage points a year apart, with technology weights ranging from 33 percent to 56 percent. A category name is not a description of a portfolio.

This guide separates the three comparisons hiding inside one return column, using figures computed on a single date so every one of them can be checked.

The three comparisons inside one return column

Read the first row first. If two lines on a chart belong to one portfolio, no amount of analysis of holdings, sectors or management will explain the difference between them, because there is nothing there to explain.

Data and method used in this article

Every figure in this article was computed on August 18, 2026, and each one can be reproduced from the definitions below.

• Returns. Annualized figures come from daily closing prices adjusted for dividends and capital gain distributions, retrieved through a public market data feed, and cover the ten year, five year, three year and one year windows ending August 14, 2026. For mutual funds the closing price is net asset value, so those are net asset value total returns. For exchange traded funds (VOO, IVV, SPY and VTI) the closing price is the market price, so those are market price total returns. The S&P 500 section below deliberately mixes the two bases, and at a spread of 0.09 points a year that basis difference is part of what the spread contains.
• Calendar years. Year end to year end on the same adjusted series. The 2026 row is a partial year to August 14, 2026.
• Correlation. Pearson correlation of daily returns over the three years ending August 14, 2026.
• Volatility. Annualized standard deviation of daily returns over the same three years, scaled by the square root of 252 trading days.
• Drawdown. The largest peak to trough decline in the daily adjusted series between November 1, 2021 and December 31, 2022, which covers the last full equity drawdown inside the window.
• Holdings. Each fund's most recently published top ten holdings as retrieved on August 18, 2026. The underlying holdings are published by the funds themselves. The feed does not expose each fund's publication date, so these comparisons read as most recently published rather than as of one stated date, and mutual funds publish on their own quarterly schedules. The feed returned nine names rather than ten for Fidelity Contrafund and Fidelity Growth Company, and the calculations use those nine, which can only lower those two funds' figures.
• Sector exposure. Sector weights are whole portfolio weights as published through the same public market data feed on August 18, 2026, using that provider's sector classification. They cover the full portfolio rather than the published top ten, so the nine name limitation noted above applies to the holdings figures and not to these.
• Overlap. The minimum weight method restricted to the published top ten lists, adding the smaller of the two weights for every company both lists contain. Because it ignores everything below the top ten, every overlap figure here is a floor rather than a full portfolio measurement, and the true figure across the whole portfolio is higher.
• Rounding. Table figures are rounded to two decimals, while every gap, spread and range quoted in the text is computed from unrounded values, so a difference recomputed from two rounded table cells can land 0.01 away from the figure in the text.

All numbers are derived estimates rather than official fund disclosures, and they sit beside each fund's official standardized performance rather than replacing it. They will differ at other dates. Past performance does not indicate future results, and nothing here is a recommendation. Returns exclude any sales load paid on purchase and exclude taxes. Where a table is sorted, the order reflects the metric it is sorted on and implies nothing about which fund is better, since no fund in this article is presented as better than another.

Comparison one: the same portfolio at more than one price

A mutual fund is a portfolio. A share class is a price and a distribution channel wrapped around that portfolio. American Funds Growth Fund of America publishes several share classes, of which the A, C, F-1 and R-6 classes are used here, and the published top ten holdings of the A class and the R-6 class are identical, company for company and weight for weight: NVDA at 5.49 percent, AVGO at 4.38 percent, META at 3.83 percent, MSFT at 3.41 percent, MU at 3.31 percent, AMZN at 3.26 percent, LLY at 2.81 percent, GOOG at 2.79 percent, GOOGL at 2.76 percent and TSLA at 2.51 percent.

One portfolio, several prices. The ten year record separates them anyway.

The dollar columns are a hypothetical illustration rather than an account result. They assume one lump sum invested ten years ago, distributions reinvested, no further purchases or redemptions, no sales charges and no taxes.

The C class trailed the R-6 class by 1.27 percentage points a year on the same holdings. Compounded over a decade on a $100,000 position that is $45,436, and the gap tracks the difference in ongoing class expenses rather than anything in the portfolio. One qualification belongs with the C class figure. Class C shares in several fund families, including this one, convert automatically to another class after a set holding period, so an investor holding for the full ten years would not have paid the C class rate throughout.

The pattern is not specific to one fund family. Four more examples, each pair being one portfolio under two labels:

The dollar column here is a hypothetical illustration on the same assumptions as the table above: one lump sum, distributions reinvested, no further transactions, no sales charges and no taxes.

Each annual gap in that table is computed before rounding, which is why the Contrafund row reads 0.09 points rather than the 0.10 that the two rounded return cells would suggest. T. Rowe Price Blue Chip Growth appears a third time later in this article as TRBCX, the investor class of the same portfolio that TBCIX and PABGX hold, and its ten year return sits between the two classes shown here.

Two things make this comparison reliable. The daily returns of each pair correlate at 0.9965 to 1.0000 over the last three years, which is what one portfolio priced two ways looks like. And the gap is stable across windows: the Growth Fund of America A and R-6 classes sat 0.34 points apart over one year, 0.37 over three, 0.35 over five and 0.38 over ten.

Two caveats belong with this comparison. The cheapest classes are usually restricted, since institutional and R-6 classes are typically reached through a retirement plan or an adviser platform rather than bought directly, so the cheaper line is not always available. And because these are net asset value returns, an A class figure already excludes any front end sales charge, which means the cost difference an investor experienced can be larger than the table shows, never smaller.

When you compare two funds and find a gap this steady, check whether you are looking at one portfolio before looking for a reason in the holdings.

Comparison two: the same index in six different wrappers

The second comparison is the one most investors think they are doing when they compare index funds. Six funds track the S&P 500. Three are mutual funds and three are exchange traded funds, they come from five different fund families, and all six own the same index.

The entire spread across six funds and ten years is 0.09 percentage points a year. That is the whole decision. A comparison tool that ranks these six by return is sorting noise, and the honest reading is that they delivered the same thing, with the remaining differences traceable to fees, to tracking and to the mix of net asset value and market price bases set out in the method, rather than to strategy.

The same holds for total market funds. Vanguard Total Stock Market compounded at 14.89 percent in the Admiral mutual fund class, 14.90 percent in the institutional class and 14.91 percent in the exchange traded fund over ten years, with the last of those three measured on a market price basis rather than on net asset value. When a comparison produces a gap of one or two basis points a year, the useful questions move elsewhere, to the account the fund sits in, the minimum, the tax treatment of distributions and whether the position can be traded intraday.

For side by side cost, holdings and exposure on any of these pairs, the fund comparison tool inside FundXLS puts them in one view.

Comparison three: one category, five very different portfolios

Now the comparison that actually rewards work. These five funds all carry the large growth category label, and the S&P 500 index fund is included as a reference point rather than as a peer.

One availability note belongs with the top line of that table, in the same spirit as the share class note earlier. Fidelity Growth Company is closed to new investors through most retail channels, so its record is not generally purchasable today.

Five funds, one label, 7.58 percentage points a year of separation over five years, from 16.675 percent down to 9.093 percent before rounding. Their daily returns correlate at 0.9504 to 0.9881 with each other across the ten possible pairs, which is high in absolute terms and still clearly below the 0.9965 and above that marks two classes of one fund. These are genuinely different portfolios.

The published holdings show why. Concentration differs sharply. The top ten weight column above runs from 34.54 percent of Growth Fund of America to 60.27 percent of Vanguard Growth Index, a range of 25.73 points, and the Fidelity Growth Company and Contrafund entries rest on nine published names rather than ten, so both are understated rather than overstated.

Sector exposure separates the same five funds by a comparable margin, measured across the whole portfolio rather than across the top ten, so this paragraph changes basis from the column above. Technology runs from 33.19 percent of Contrafund to 56.16 percent of Vanguard Growth Index, a range of 22.97 points. The two funds with the largest healthcare weights, Fidelity Growth Company at 12.60 percent and Contrafund at 10.09 percent, are not the two with the largest technology weights. Contrafund also holds 11.03 percent in financial services against 2.91 percent for Fidelity Growth Company. Neither range is decisive on its own, and the point is that two funds under one label differ on both axes at once.

Pairwise overlap in the published top ten lists confirms the same point from another direction:

Two funds in one category can share a fifth of their headline positions or better than two fifths. That range is the reason the category label cannot substitute for the comparison. To see the whole portfolio version of this number rather than the top ten floor, run the pair through the mutual fund overlap calculator.

What past returns can and cannot rank

The five year column above ranks these funds. So does the ten year column, and it ranks them differently: Blue Chip Growth is last of the five over five years and fourth over ten. Calendar year results explain why any single window is fragile.

Across those eleven periods, Fidelity Growth Company finished first six times and fifth of six twice, in 2018 and 2022. Blue Chip Growth finished first twice, in 2018 and 2023, and last four times. The index fund finished last in six of the eleven periods while producing the smallest drawdown of the group, more than eight points shallower than the next fund. Growth Fund of America finished first in none of them.

None of that identifies a better fund. It shows that a ranking by past return is a ranking of the window you chose, which is the single strongest argument for comparing holdings, concentration and drawdown alongside the return column rather than after it. Our related article on comparing mutual funds beyond past returns works through that idea in more depth.

The comparison most portfolios need: overlap with what you already own

A fund comparison is usually framed as fund against fund. The more useful version for an existing portfolio is fund against what is already held, because a new position only adds something if it holds something new.

Measured against a plain S&P 500 index fund, using published top ten lists only:

At least a quarter of each of these funds duplicates an S&P 500 index fund from the top ten holdings alone, before the several hundred shared positions further down are counted. That is not a fault in any of the funds, since large United States growth managers pick from the same universe of large United States companies. It is simply a fact about the combination, and it only appears when the comparison includes the portfolio rather than stopping at the two funds on screen.

For a whole portfolio rather than one pair at a time, the portfolio x-ray report inside FundXLS looks through fund holdings to the underlying companies.

Running the comparison in a browser

Everything above was computed from published data, and none of it needs a spreadsheet. FundXLS, the fund and ETF research platform on MarketXLS, is built for these checks and runs them in a browser:

1. Open the mutual fund comparison tool and enter the two tickers. The result puts cost, holdings and exposure side by side in one view.
2. Check the share class question first. If two funds carry the same fund name and the same top holdings at the same weights, you are comparing prices, not portfolios.
3. Run the pair through the mutual fund overlap calculator for weighted overlap across the published holdings rather than the top ten floor used in this article.
4. Read the shared holdings list, not only the percentage. Overlap concentrated in eight companies means something different from overlap spread across three hundred.
5. Compare against what the portfolio already holds, using the portfolio x-ray for the look through view. If the comparison involves exchange traded funds, the ETF comparison tool covers the same ground for those.

The reason to run this in a web tool rather than by hand is that every input moves. Holdings are republished, weights drift, share classes are added and merged, and a return window that ended last quarter ranks funds differently from one that ends today.

What a fund comparison cannot tell you

Precision about limits matters more here than in most analysis, because fund comparison output looks authoritative:

• A comparison describes, it does not recommend. Every figure in this article states what happened through August 14, 2026. None of it establishes what any fund will do next, and none of it is suitable as the basis for a decision on its own.
• Past returns are a record, not a forecast. The calendar table shows the same funds occupying opposite ends of the ranking in different years.
• Net asset value returns exclude what you paid to get in. Sales charges and taxes sit outside these figures and can exceed the gaps shown.
• Disclosure timing limits holdings work. Many mutual funds publish holdings quarterly, so any holdings comparison reflects the most recent published files rather than today's positions.
• Category labels are assigned by data providers. They group funds by observed characteristics, and, as the 7.58 point spread shows, membership of one category says little about how two funds behave.
• Low overlap is not diversification. Two funds can hold entirely different companies of the same size, sector and country and still move together.

Frequently asked questions

What should I compare when comparing two mutual funds? Start by establishing whether the two funds are actually two portfolios. Compare the fund name, the top holdings and their weights first, because two share classes of one fund need no further analysis beyond cost. If the portfolios genuinely differ, compare holdings overlap, concentration in the top ten, sector exposure, volatility, drawdown in a falling market and cost, and treat the return column as one input among those rather than the summary of them.

Why do two share classes of the same mutual fund show different returns? Because the classes charge different amounts for the same portfolio. Ongoing expenses are deducted from net asset value, so a costlier class compounds at a lower rate on identical holdings. In the data above, the gap between the cheapest and costliest class of one fund ranged from 0.09 to 1.27 percentage points a year, and the daily returns of each pair correlated at 0.9965 or higher.

Is a lower cost share class always available? No. Institutional, R-6 and similar classes are commonly reached only through a retirement plan, an adviser platform or a large minimum investment, so the cheaper line in a comparison may not be purchasable in a given account. Availability is worth checking before the cost difference means anything in practice.

Do index funds tracking the same index really perform the same? Very nearly. Six S&P 500 funds from five families finished within 0.09 percentage points a year of one another over ten years to August 14, 2026. Differences at that scale come from fees, from tracking and from the mix of return bases used, since mutual fund figures are net asset value returns while exchange traded fund figures are market price returns. They do not come from strategy, which shifts the comparison to the account type, the minimum, the wrapper and how distributions are treated.

How much do two funds in the same category overlap? It varies widely, which is the point. Among five large growth funds, overlap measured on published top ten holdings alone ran from 20.27 percent to 42.57 percent across the ten pairs, and those are floors rather than full portfolio figures. The category label sets no expectation about the answer, so the pair has to be measured.

Can I compare a mutual fund against an exchange traded fund? Yes, and the arithmetic is identical. The caveat is disclosure timing, since exchange traded funds generally publish holdings daily while many mutual funds disclose quarterly, so the comparison reflects the most recent published files on each side. Vanguard Total Stock Market illustrates how small the wrapper difference can be, at 14.89 percent annualized in the Admiral mutual fund class against 14.91 percent in the exchange traded fund over ten years, and even that 0.02 point difference spans two return bases, net asset value on one side and market price on the other.

The bottom line

Mutual fund comparison is three separate questions wearing one interface. Two share classes of one portfolio differ only in price, and that price showed up as 0.09 to 1.27 percentage points a year across the pairs above, worth $45,436 on a $100,000 position over a decade in the widest case. That dollar figure is a hypothetical lump sum illustration, and no single class C holder would have experienced it in full, because of the automatic class conversion described earlier. Six funds tracking one index differed by 0.09 percentage points a year in total, so ranking them by return sorts noise. Five funds sharing one category label differed by 7.58 percentage points a year, held between 20 and 43 percent of their top ten positions in common, and carried technology weights from 33 percent to 56 percent.

The order that works is: establish whether the two funds are one portfolio, then compare holdings, concentration and drawdown, then read the return column against the window it came from, and finally check the pair against what the portfolio already owns. All four steps run in a browser.

Start with two funds you already hold on the FundXLS platform. For a walkthrough of the fund research tools applied to a real portfolio, you can book a demo.

Related reading: what to compare in a side by side fund view, how to use a mutual fund screener, ETF and mutual fund structural differences, and filtering a fund universe by cost and category.

Disclaimer and disclosures

This article is educational, and it promotes MarketXLS products. It is not investment advice, tax advice, or a recommendation to buy, sell, or hold any security or fund share class. MarketXLS is a software provider and is not a registered investment adviser, and nothing here is personalized advice. Consider speaking with a qualified professional about your own circumstances, including the tax consequences of any portfolio change.

All performance, correlation and holdings figures in this article were computed by MarketXLS on August 18, 2026 from daily closing prices adjusted for dividends and capital gain distributions and from the most recently published top ten holdings, retrieved from public market data sources on that date. Mutual fund returns are net asset value total returns and exchange traded fund returns are market price total returns, all covering the periods ending August 14, 2026, they exclude sales charges and taxes, and past performance does not indicate future results. Holdings and weights change over time and published holdings files carry different publication dates, so the figures will differ at other dates. These are derived estimates, and MarketXLS does not warrant their accuracy or completeness. The featured image is an illustration of the interface and does not display live results.

All fund names, ticker symbols, index names and trademarks are the property of their respective owners. MarketXLS is not affiliated with, sponsored by, or endorsed by any fund provider, index provider, or exchange named in this article. See the MarketXLS disclaimer and terms of use for further detail.