IWY vs. MGK

Last updated Jun 6, 2026

IWY (iShares Russell Top 200 Growth ETF) and MGK (Vanguard Mega Cap Growth ETF) are both Large Cap Growth Equities funds - IWY tracks the Russell Top 200 Growth Index while MGK tracks the CRSP US Mega Cap Growth Index. Both are passively managed. Over the past 10 years, IWY returned 19.21%/yr vs 18.77%/yr for MGK. With a 0.98 correlation, they move nearly in lockstep. IWY charges 0.20%/yr vs 0.05%/yr for MGK.

Performance

IWY vs. MGK - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Russell Top 200 Growth ETF (IWY) and Vanguard Mega Cap Growth ETF (MGK). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, IWY achieves a 4.09% return, which is significantly lower than MGK's 6.05% return. Both investments have delivered pretty close results over the past 10 years, with IWY having a 19.21% annualized return and MGK not far behind at 18.77%.

IWY

• 1D: -3.23%
• 1M: 0.51%
• YTD: 4.09%
• 6M: 3.11%
• 1Y: 23.50%
• 3Y*: 24.28%
• 5Y*: 15.76%
• 10Y*: 19.21%

MGK

• 1D: -3.73%
• 1M: 0.69%
• YTD: 6.05%
• 6M: 4.91%
• 1Y: 25.99%
• 3Y*: 25.22%
• 5Y*: 15.40%
• 10Y*: 18.77%

*Multi-year figures are annualized to reflect compound growth (CAGR)

IWY vs. MGK - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IWY iShares Russell Top 200 Growth ETF	4.09%	18.19%	34.89%	46.49%	-29.91%	31.05%	39.01%	36.20%	-0.72%	31.69%
MGK Vanguard Mega Cap Growth ETF	6.05%	20.67%	32.94%	51.67%	-33.59%	28.58%	41.01%	37.38%	-2.91%	29.49%

Correlation

The correlation between IWY and MGK is 0.99 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.99
Correlation (3Y) Calculated over the trailing 3-year period	0.99
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (10Y) Calculated over the trailing 10-year period	0.99
Correlation (All Time) Calculated using the full available price history since Sep 29, 2009	0.98

The correlation between IWY and MGK has been stable across timeframes, ranging from 0.98 to 0.99 - a consistent structural relationship.

IWY vs. MGK - Sectors Allocation Comparison

Sectors	IWY	MGK
Technology	54.9%	56.1%
Communication Services	13.9%	17.3%
Consumer Cyclical	11.4%	12.8%
Healthcare	6.6%	4.5%
Financial Services	5.6%	4.5%
Industrials	4.0%	1.1%
Consumer Defensive	3.0%	0.4%
Utilities	1.1%	1.2%
Real Estate	0.3%	1.3%
Basic Materials	0.3%	0.7%
Energy	0.0%	-

Return for Risk

IWY vs. MGK — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

IWY

IWY Risk / Return Rank: 38
IWY Sharpe Ratio Rank: 44
IWY Sortino Ratio Rank: 41
IWY Omega Ratio Rank: 41
IWY Calmar Ratio Rank: 29
IWY Martin Ratio Rank: 32

MGK

MGK Risk / Return Rank: 40
MGK Sharpe Ratio Rank: 46
MGK Sortino Ratio Rank: 43
MGK Omega Ratio Rank: 44
MGK Calmar Ratio Rank: 32
MGK Martin Ratio Rank: 35

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

IWY vs. MGK - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Russell Top 200 Growth ETF (IWY) and Vanguard Mega Cap Growth ETF (MGK). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

	IWY	MGK	Difference
Sharpe ratio: Return per unit of total volatility	1.49	1.57	-0.08
Sortino ratio: Return per unit of downside risk	2.03	2.13	-0.10
Omega ratio: Gain probability vs. loss probability	1.26	1.28	-0.01
Calmar ratio: Return relative to maximum drawdown	1.42	1.55	-0.13
Martin ratio: Return relative to average drawdown	4.62	5.32	-0.70
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

IWY vs. MGK - Sharpe Ratio Comparison

The current IWY Sharpe Ratio is 1.49, which is comparable to the MGK Sharpe Ratio of 1.57. The chart below compares the historical Sharpe Ratios of IWY and MGK, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	IWY	MGK	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.49	1.57	-0.08
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.74	0.68	+0.05
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.92	0.86	+0.06
Sharpe Ratio (All Time) Calculated using the full available price history	0.91	0.64	+0.26

Drawdowns

IWY vs. MGK - Drawdown Comparison

The maximum IWY drawdown since its inception was -32.68%, smaller than the maximum MGK drawdown of -47.97%. Use the drawdown chart below to compare losses from any high point for IWY and MGK.

Drawdown Indicators

	IWY	MGK	Difference
Max Drawdown Largest peak-to-trough decline	-32.68%	-47.97%	+15.29%
Max Drawdown (1Y) Largest decline over 1 year	-16.63%	-16.85%	+0.22%
Max Drawdown (3Y) Largest decline over 3 years	-23.22%	-23.36%	+0.14%
Max Drawdown (5Y) Largest decline over 5 years	-32.68%	-36.01%	+3.33%
Max Drawdown (10Y) Largest decline over 10 years	-32.68%	-36.01%	+3.33%
Current Drawdown Current decline from peak	-4.67%	-4.99%	+0.32%
Average Drawdown Average peak-to-trough decline	-4.75%	-7.47%	+2.72%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.10%	4.90%	+0.20%

Volatility

IWY vs. MGK - Volatility Comparison

The current volatility for iShares Russell Top 200 Growth ETF (IWY) is 4.81%, while Vanguard Mega Cap Growth ETF (MGK) has a volatility of 5.40%. This indicates that IWY experiences smaller price fluctuations and is considered to be less risky than MGK based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IWY	MGK	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.81%	5.40%	-0.59%
Volatility (6M) Calculated over the trailing 6-month period	12.12%	12.96%	-0.84%
Volatility (1Y) Calculated over the trailing 1-year period	15.88%	16.66%	-0.78%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.51%	22.68%	-1.17%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.00%	21.91%	-0.91%

IWY vs. MGK - Expense Ratio Comparison

IWY has a 0.20% expense ratio, which is higher than MGK's 0.05% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

IWY vs. MGK - Dividend Comparison

IWY's dividend yield for the trailing twelve months is around 0.34%, more than MGK's 0.33% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IWY iShares Russell Top 200 Growth ETF	0.34%	0.36%	0.42%	0.68%	0.88%	0.50%	0.71%	1.06%	1.32%	1.26%	1.51%	1.58%
MGK Vanguard Mega Cap Growth ETF	0.33%	0.35%	0.43%	0.50%	0.70%	0.41%	0.65%	0.85%	1.12%	1.23%	1.53%	1.43%

Frequently Asked Questions

Can I hold both IWY and MGK in my portfolio?

With a correlation of 0.99, IWY and MGK move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, IWY or MGK?

MGK has higher volatility (5.40%) compared to IWY (4.81%). In terms of maximum drawdown, IWY dropped -32.68% vs MGK's -47.97%.

Which ETF is better, IWY or MGK?

On 10-year performance, IWY leads with 19.21% vs 18.77% for MGK. On fees, MGK is cheaper at 0.05% per year. On volatility, IWY has been the lower-risk option at 4.81%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, IWY or MGK?

Over the 10-year period, IWY has performed better with a 19.21% return vs 18.77%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, IWY or MGK?

MGK is cheaper with a 0.05% expense ratio, compared with 0.20% for IWY.

Which ETF pays a higher dividend yield, IWY or MGK?

IWY and MGK have nearly identical dividend yields, around 0.34%.

What is the main difference between IWY and MGK?

IWY tracks Russell Top 200 Growth Index, while MGK tracks CRSP US Mega Cap Growth Index. They also come from different issuers: iShares and Vanguard. Their fees differ too: 0.20% for IWY and 0.05% for MGK.

Which has better risk-adjusted returns?

MGK currently has the higher Sharpe Ratio (1.57 vs 1.49), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.