index
MSCI ACWI IMI
Broad global equities including small caps
Index Battle · Evidence-first comparison
MSCI ACWI IMI vs S&P 500: Which Exposure Fits Your Portfolio?
At one end, close to the entire investable global equity market. At the other, five hundred large US companies.
Last reviewed: 26 August 2026IndependentNo paid placementsInformational only
vs
index
S&P 500
US large-cap equities
Overall verdict
This is the widest breadth decision Grovcap covers. MSCI ACWI IMI aims to capture roughly 99% of the global investable equity opportunity set, across developed and emerging markets and all three size segments. The S&P 500 is a concentrated, committee-selected slice of that same universe — one that has represented a large share of global market value in recent years, which is exactly why the two can look similar over short windows despite being structurally very different.
Quick Decision
Choose MSCI ACWI IMI if…
the objective is to own the market rather than to select part of it, and you accept emerging-market and small-cap risk as part of that.
Choose S&P 500 if…
you have a considered reason to concentrate on US large caps and are prepared for the outcome to depend on a single country's market and currency.
Either can make sense if…
the portfolio's country and currency exposure is measured after the decision, not assumed from the fund's name.
At a glance
Entity characteristics—not reference-product fees.
| Characteristic | MSCI ACWI IMI | S&P 500 |
|---|---|---|
| Exposure | Broad global equities including small caps | US large-cap equities |
| Geography | Global | United States |
| Market coverage | Large, mid and small cap | Large cap |
| Emerging markets | Included | Not included |
| Small caps | Included | Not included |
| Weighting | Market-cap weighted | Market-cap weighted |
| Index provider | MSCI | S&P Dow Jones Indices |
Five key differences
- 1.Exposure: Broad global equities including small caps compared with US large-cap equities.
- 2.Geography: Global compared with United States.
- 3.Market coverage: Large, mid and small cap compared with Large cap.
- 4.Emerging markets: Included compared with Not included.
- 5.Small caps: Included compared with Not included.
Decision scorecard
ExposureDepends
GeographyDepends
Market coverageDepends
Emerging marketsDepends
Small capsDepends
“Depends” means the category reflects an investor objective, not universal superiority.
Coverage, countries and sectors
Verified holdings, concentration, country and sector datasets are not currently connected. When available, each dataset will be labelled as official index data or Reference ETF holdings; listing domicile will not be presented as economic revenue exposure.
What this means in a portfolio
The S&P 500 is a subset of MSCI ACWI IMI. Owning both is a US large-cap overweight; the honest way to describe it is a deliberate home-market-of-returns tilt, not a two-fund diversification strategy.
Common mistake
Concluding from a high US weight inside ACWI IMI that the two are 'basically the same'. The residual difference is precisely the diversification the broad index is there to provide.
Historical comparison basis
Historical performance is represented using Grovcap-selected reference exchange-traded products. It is not the official index or spot return series. Fund or ETP returns can differ because of fees, taxes, tracking, cash positions, product structure and other implementation effects. Differences can reflect TER, tracking difference, withholding taxes, sampling, securities lending, cash drag, operating expenses, currency conversion and inception date.
No period is currently comparable across both reference products on a like-for-like currency, basis and reporting-date footing, so no return figures are shown. Grovcap never renders a missing return as 0.00%.
Grovcap does not currently hold a daily net-asset-value time series for these products. Indexed performance charts, annualised volatility, maximum drawdown and return-per-risk therefore remain unavailable rather than being estimated from period returns.
Reference instruments used
One canonical European exchange-traded product per exposure, chosen by published rules: exact benchmark family, active and published, plain long-only, then accumulating, unhedged, longest usable history and largest established product.
MSCI ACWI IMI reference product
State Street® SPDR® MSCI All Country World Investable Market UCITS ETF (Acc)
- ISIN
- IE00B3YLTY66
- Product type
- UCITS ETF
- Provider
- Spdr
- Tracked benchmark
- MSCI ACWI IMI (All Country World Investable Market Index) Index
- Distribution
- Accumulating
- Currency hedging
- Unhedged
- Replication
- Physical
- Domicile
- Ireland
- Base currency
- USD
- Ongoing charge (TER)
- 0.17%
- Fund size
- $7.56bn
- Inception
- 13 May 2011
Selected deterministically from 2 eligible products in the Grovcap database — never by commercial arrangement.
S&P 500 reference product
Xtrackers S&P 500 Swap UCITS ETF 1C
- ISIN
- LU0490618542
- Product type
- UCITS ETF
- Provider
- Xtrackers
- Tracked benchmark
- S&P 500 INDEX
- Distribution
- Accumulating
- Currency hedging
- Unhedged
- Replication
- Synthetic
- Domicile
- LU
- Base currency
- USD
- Ongoing charge (TER)
- 0.15%
- Fund size
- €8.17bn
- Inception
- 26 Mar 2010
Selected deterministically from 49 eligible products in the Grovcap database — never by commercial arrangement.
Continue researching
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Disclaimer
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