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Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.

ETFIQetfiq.com · independent ETF data

ITOT vs MDY: how they differ

ITOT and MDY hold 5% of their weight in the same names, and ITOT returned more over the year.

iShares Core S&P Total U.S. Stock Market ETF and SPDR S&P MidCap 400 ETF Trust.

What they hold in common

By the books each fund has filed, ITOT and MDY hold 5% of their money in the same securities at the same weight.

Positions ITOT and MDY both hold, largest shared weight first
HoldingITOTMDY
Twilio, Inc.0.04%0.86%
Carpenter Technology Corp.0.04%0.85%
MKS, Inc.0.04%0.83%
Curtiss-Wright Corp.0.04%0.77%
Entegris, Inc.0.04%0.76%
ATI, Inc.0.04%0.74%
Illumina, Inc.0.04%0.73%
MasTec, Inc.0.04%0.71%
Sterling Infrastructure, Inc.0.04%0.71%
Woodward, Inc.0.04%0.70%
Everpure, Inc.0.03%0.69%
MACOM Technology Solutions Holdings, Inc0.03%0.69%
Largest positions each one holds and the other does not
Only in ITOTOnly in MDY
NVIDIA Corp. 6.64%NVENT ELECTRIC PLC 0.76%
Apple, Inc. 5.82%TECHNIPFMC PLC 0.73%
Microsoft Corp. 3.80%FABRINET 0.56%
Amazon.com, Inc. 3.20%ROIVANT SCIENCES LTD 0.44%
Alphabet, Inc. 2.87%JAZZ PHARMACEUTICALS PLC 0.42%
Broadcom, Inc. 2.45%RENAISSANCERE HOLDINGS LTD 0.37%
Alphabet, Inc. 2.29%SHARKNINJA INC 0.30%
Micron Technology, Inc. 1.78%CNH INDUSTRIAL NV 0.27%

Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026.

ITOT and MDY on the fields both publish, as of Sep 12, 2026. Source: ETFIQ.
ITOT
iShares Core S&P Total U.S. Stock Market ETF
MDY
SPDR S&P MidCap 400 ETF Trust
Where it sitsCore index fundCore index fund
IssueriSharesState Street
What it isCore S&P Total U.S. Stock MarketS&P MidCap 400, book from IJH
Total return, 1 year+17.2%+13.0%
S&P 500 over the same days+17.5%+17.5%
Gap to the S&P 500−0.3 pts−4.5 pts
Expense ratio0.03%0.23%
Already in the S&P 50088.3%0.0%
Holdings2497400

ITOT in plain words

ITOT is an index equity fund tracking the Core S&P Total U.S. Stock Market. Over the year to Sep 11, 2026 it returned +17.2% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.03% a year. By its holdings filed for Jun 30, 2026, 88% of the fund by weight is stocks the S&P 500 also holds, across 2497 positions, with the top ten at 32.2%.

MDY in plain words

MDY is an index equity fund tracking the S&P MidCap 400. Over the year to Sep 11, 2026 it returned +13.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.23% a year. By its holdings filed for Jun 30, 2026, 0% of the fund by weight is stocks the S&P 500 also holds, across 400 positions, with the top ten at 7.7%. It sat 5.3% below its high of Aug 14, 2026 on Sep 11, 2026.

Questions people ask

Which returned more over the last year, ITOT or MDY?
In the year to Sep 12, 2026, with distributions reinvested, ITOT returned +17.2% and MDY returned +13.0%, so ITOT returned more. One year is one year; the longer windows are in the table.
Which is cheaper, ITOT or MDY?
ITOT charges 0.03% a year and MDY charges 0.23%, so ITOT is cheaper. Fees come from each fund's prospectus.
How much do ITOT and MDY overlap with the S&P 500?
By their latest filed holdings, 88% of ITOT and 0% of MDY by weight is stocks the S&P 500 already holds. Between the two funds, 5% of their books are the same securities at the same weight.

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Where these figures came from

ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.

ITOT against MDY, ETFIQ, data as of Sep 12, 2026. Every figure is arithmetic on a named public source; the method is at etfiq.com/methodology. A comparison is not a recommendation.

Cite this page. ETFIQ, ITOT against MDY, data as of Sep 12, 2026. https://etfiq.com/compare/any/ITOT-MDY Free to use with attribution; the underlying files are at Open data.

A comparison is not a recommendation. Standards and sources