Data as of Oct 28, 2026.
IWB vs MGK: Differences, Returns & Fees
Over the year to Oct 28, 2026, IWB returned +13.1% to MGK's +7.8%; 47% of their weight is in the same names.
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Net assets: $49.1bn on Oct 28, 2026 for iShares Russell 1000 ETF, and $34.9bn on Sep 30, 2026 for Vanguard Morningstar Mega Cap Growth ETF.
Pair scorecard
MGK costs 0.10 points a year less; their one-year returns differ by 5.3 points; IWB is 1.4 times larger.
| Measure | IWB | MGK |
|---|---|---|
| Return | ||
| Total return, 1 year | +13.1% | +7.8% |
| Drawdown | ||
| Below its high | 4.4%, high on Oct 6, 2026 | |
| Benchmark | ||
| What it tracks | Russell 1000 Index | Morningstar US Mega Cap Growth Index |
| Cost and size | ||
| Expense ratio | 0.15% | 0.05% |
| Net assets, as of Sep 30, 2026 | $48.6bn | $34.9bn |
| Holdings | ||
| Holdings in common | 47% | |
| Top ten holdings, share of the fund | 35.3% | 64.5% |
Holdings in common uses holdings dated Sep 30, 2026 and Oct 27, 2026. Method
Risk and return
Jan 4, 2008 to Oct 23, 2026 · 981 weekly returnsMGK returned more: +1,024.1% to +643.7%. IWB swung slightly less: 18.4% to 19.5%. MGK fell slightly less at its worst: −46.4% to −51.3%.
Full scorecard
9 measures, with how each is measured Open ↓
| Measure | IWB | MGK | Edge | How it is measured |
|---|---|---|---|---|
| Return | ||||
| Total return | +643.7% | +1,024.1% | MGK | Price change plus distributions, reinvested. |
| Annualized | +11.2% | +13.7% | MGK | Total return as a yearly rate. |
| Price return | +440.3% | +823.8% | MGK | Price change alone, distributions left out. |
| Risk | ||||
| Volatility | 18.4% | 19.5% | IWB (slight) | Spread of weekly returns, annualized. Lower is steadier. |
| Downside deviation | 12.9% | 13.3% | IWB (slight) | Like volatility, counting only weeks below the Treasury bill rate. |
| Max drawdown | −51.3% | −46.4% | MGK (slight) | Deepest fall from a high to the low after it. |
| Risk-adjusted | ||||
| Sharpe | 0.59 | 0.68 | MGK | Return above Treasury bills per unit of volatility. |
| Sortino | 0.84 | 1.00 | MGK | Return above Treasury bills per unit of downside deviation. |
| Calmar | 0.22 | 0.30 | MGK | Annualized return divided by the max drawdown. |
Computed by ETFIQ from Tiingo daily prices and ETFIQ's distribution records, 981 weekly returns. Cash rate: the 13-week Treasury bill.
What they share
By the books each fund has filed, IWB and MGK hold 47% of their money in the same securities at the same weight. Holdings dated Sep 30, 2026 and Oct 27, 2026.
half
47% in common
Only in one fund ↓
Side by side
IWB and MGK on the fields both publish, as of Oct 28, 2026. Source: ETFIQ.
IWB and MGK do different jobs. What does each one do in a portfolio?
- What each follows. IWB follows Russell 1000 Index and MGK follows Morningstar US Mega Cap Growth Index.
- Holdings in common. 47% of the weight is in the same securities (holdings dated Oct 27, 2026 and Sep 30, 2026).
- One-year total return. Over 1 year to Oct 28, 2026 IWB returned +13.1% and MGK +7.8% with distributions reinvested, a gap of 5.3 points.
Data as of Oct 28, 2026.
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IWB
IWB tracks the Russell 1000. Over the year to Oct 28, 2026 it returned +13.1% with distributions reinvested, against +13.2% 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 27, 2026, 92% of the fund by weight is stocks the S&P 500 also holds, across 1,025 positions, with the top ten at 35.3%.
MGK
MGK tracks an index of Mega Cap Growth. Over the year to Oct 28, 2026 it returned +7.8% with distributions reinvested. The prospectus expense ratio is 0.05% a year. By its holdings published by its issuer as of Sep 30, 2026, 99% of the fund by weight is stocks the S&P 500 also holds, across 54 positions, with the top ten at 64.5%. It sat 4.4% below its high of Oct 6, 2026 on Oct 28, 2026.
Questions people ask
- Which returned more over the last year, IWB or MGK?
- In the year to Oct 28, 2026, with distributions reinvested, IWB returned +13.1% and MGK +7.8%.
- Which is cheaper, IWB or MGK?
- MGK is cheaper, by 0.10 percentage points a year. That is about $10 on $10,000 held for a year. Fees come from each fund's prospectus.
Links are sources, not endorsements. 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.
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ETFIQ, IWB against MGK, data as of Oct 28, 2026. https://etfiq.com/compare/any/iwb-vs-mgk
ETFIQ. (Oct 28, 2026). IWB against MGK. Retrieved from https://etfiq.com/compare/any/iwb-vs-mgk
[IWB against MGK (ETFIQ, Oct 28, 2026)](https://etfiq.com/compare/any/iwb-vs-mgk)
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