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IWB vs USMC: Differences, Returns & Fees

IWB and USMC hold 44% of their weight in the same names, and IWB returned +16.6% over the year. Net assets: $49.6bn on Oct 9, 2026 for iShares Russell 1000 ETF, and $5.2bn on Oct 8, 2026 for Principal U.S. Mega-Cap ETF.

USMC costs 0.03 points a year less; their one-year returns differ by 1.8 points; IWB is 9.6 times larger.

IWB vs USMC: Differences, Returns & Fees
IWBUSMC
Expense ratio0.15%0.12%
Net assets, as of Oct 8, 2026$49.4bn$5.2bn
Total return, 1 year+16.6%+14.8%
What it tracksRussell 1000 IndexNo index, actively managed
Holdings in common44%
Top ten holdings, share of the fund36.1%54.3%

Holdings in common uses holdings dated Jun 30, 2026 and Oct 9, 2026.

+16.6%
IWB total return, 1 year
+14.8%
USMC total return, 1 year
0.15%
IWB expense ratio
0.12%
USMC expense ratio

What they hold in common

By the books each fund has filed, IWB and USMC hold 44% of their money in the same securities at the same weight. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026 and Oct 9, 2026.

half

44% in common

Positions both hold, largest shared weight first
Holding IWB USMC
NVIDIA 7.44% 7.54%
APPLE 6.77% 6.63%
MICROSOFT 5.53% 4.30%
AMAZON.COM INC 3.54% 3.60%
ALPHABET CLASS A 2.85% 5.80%
BROADCOM INC 2.34% 4.77%
META PLATFORMS CLASS A 2.20% 3.51%
MICRON TECHNOLOGY 1.61% 8.75%
TESLA INC 1.56% 2.31%
BERKSHIRE HATHAWAY INC CLASS B 1.34% 3.10%
ELI LILLY 1.31% 2.52%
JPMORGAN CHASE & CO 1.24% 4.40%
Only in IWB
ALPHABET CLASS C 2.30%
ADVANCED MICRO DEVICES 1.38%
EXXONMOBIL HOLDINGS CORP 0.97%
INTEL CORPORATION 0.67%
CISCO SYSTEMS INC 0.65%
PALANTIR TECHNOLOGIES CLASS A 0.65%
APPLIED MATERIAL INC 0.56%
LAM RESEARCH 0.55%
Only in USMC
General Electric Co 3.41%
Exxon Mobil Corp 1.99%

Check overlap with more funds →

On the same fields

IWB
iShares Russell 1000 ETF
USMC
Principal U.S. Mega-Cap ETF
Where it sits Stock ETF Stock ETF
Issuer iShares Principal
What it is Tracks the Russell 1000 Actively managed
Total return, 1 year +16.6% +14.8%
Its benchmark over the same days +16.8% (VONE) +17.3% (VOO)
Gap to its benchmark −0.1 pts vs VONE −2.5 pts vs VOO
Expense ratio 0.15% 0.12%
Already in the S&P 500 91.7% 99.8%
Holdings 1025 26
Net assets, IWB as of Oct 9, 2026 and USMC as of Oct 8, 2026 $49.6bn $5.2bn

IWB and USMC on the fields both publish, as of Oct 9, 2026. Source: ETFIQ.

About IWB

IWB tracks the Russell 1000. Over the year to Oct 9, 2026 it returned +16.6% with distributions reinvested, against +16.8% for its benchmark, the Russell 1000 Index. The prospectus expense ratio is 0.15% a year. By its holdings published by its issuer for Oct 9, 2026, 92% of the fund by weight is stocks the S&P 500 also holds, across 1,025 positions, with the top ten at 36.1%.

About USMC

USMC is actively managed and tracks no index. Over the year to Oct 9, 2026 it returned +14.8% with distributions reinvested, against +17.3% for its benchmark, the S&P 500 Index. The prospectus expense ratio is 0.12% a year. By its holdings filed for Jun 30, 2026, 100% of the fund by weight is stocks the S&P 500 also holds, across 26 positions, with the top ten at 54.3%.

Questions people ask

Which returned more over the last year, IWB or USMC?
In the year to Oct 9, 2026, with distributions reinvested, IWB returned +16.6% and USMC +14.8%.
Which is cheaper, IWB or USMC?
USMC is cheaper, by 0.03 percentage points a year. That is about $3 on $10,000 held for a year. Fees come from each fund's prospectus.
How much do IWB and USMC overlap with the S&P 500?
By their latest filed holdings, 92% of IWB and 100% of USMC by weight is stocks the S&P 500 already holds.
Other comparisons
DSI vs IWBIWB vs TSPAIWB vs THROIWB vs MGCQUAL vs USMCSCHB vs USMCRDVY vs USMCUSMC vs USMV
IWB on its own →USMC on its own →Hold both: look the portfolio through →Rankings →Standards and sources →
Where these figures came from
IWB filings on SEC EDGAR ↗IWB prospectus with the expense ratio (SEC) ↗iShares page for IWB ↗USMC filings on SEC EDGAR ↗USMC prospectus with the expense ratio (SEC) ↗Principal website ↗

ETFIQ links to the documents behind every figure; a link is not an endorsement. A comparison is not a recommendation.

How this is computed

Overlap adds up the smaller of the two weights for each security both funds hold.

Cite this pageCitation, APA and Markdown

ETFIQ, IWB against USMC, data as of Oct 9, 2026. https://etfiq.com/compare/any/iwb-vs-usmc

Open data

Free to use with attribution for figures ETFIQ computes; issuer data stays under its owner's terms.