IMCB vs. SIZE

Last updated Jun 3, 2026

IMCB (iShares Morningstar Mid-Cap ETF) and SIZE (iShares MSCI USA Size Factor ETF) are both Mid Cap Blend Equities funds from iShares - IMCB tracks the IMCB-US - Morningstar U.S. Mid Cap Index while SIZE tracks the MSCI USA Low Size Index. Both are passively managed. Over the past 10 years, IMCB returned 11.35%/yr vs 11.83%/yr for SIZE. Their correlation of 0.90 suggests significant overlap in exposure. IMCB charges 0.04%/yr vs 0.15%/yr for SIZE.

Performance

IMCB vs. SIZE - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Morningstar Mid-Cap ETF (IMCB) and iShares MSCI USA Size Factor ETF (SIZE). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, IMCB achieves a 15.00% return, which is significantly higher than SIZE's 9.81% return. Both investments have delivered pretty close results over the past 10 years, with IMCB having a 11.35% annualized return and SIZE not far ahead at 11.83%.

IMCB

• 1D: 1.17%
• 1M: 4.93%
• YTD: 15.00%
• 6M: 15.90%
• 1Y: 24.63%
• 3Y*: 17.94%
• 5Y*: 9.00%
• 10Y*: 11.35%

SIZE

• 1D: 0.27%
• 1M: 3.79%
• YTD: 9.81%
• 6M: 10.74%
• 1Y: 19.97%
• 3Y*: 16.20%
• 5Y*: 8.37%
• 10Y*: 11.83%

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

IMCB vs. SIZE - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IMCB iShares Morningstar Mid-Cap ETF	15.00%	10.25%	15.10%	16.37%	-16.09%	22.81%	13.35%	31.49%	-11.53%	19.70%
SIZE iShares MSCI USA Size Factor ETF	9.81%	10.51%	14.37%	17.78%	-15.86%	25.05%	16.26%	28.97%	-6.59%	18.76%

Correlation

The correlation between IMCB and SIZE is 0.95 - 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	0.95
Correlation (3Y) Calculated over the trailing 3-year period	0.97
Correlation (5Y) Calculated over the trailing 5-year period	0.98
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Apr 19, 2013	0.90

The correlation between IMCB and SIZE has been stable across timeframes, ranging from 0.90 to 0.98 - a consistent structural relationship.

IMCB vs. SIZE - Sectors Allocation Comparison

Sectors	IMCB	SIZE
Technology	21.3%	19.9%
Industrials	19.0%	16.1%
Financial Services	12.0%	13.5%
Consumer Cyclical	9.0%	9.8%
Healthcare	7.9%	9.6%
Energy	7.4%	5.2%
Utilities	6.2%	5.5%
Basic Materials	5.3%	4.8%
Consumer Defensive	5.1%	5.7%
Real Estate	4.3%	5.7%
Communication Services	2.3%	4.1%

Return for Risk

IMCB vs. SIZE — Risk / Return Rank

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

IMCB

IMCB Risk / Return Rank: 59
IMCB Sharpe Ratio Rank: 56
IMCB Sortino Ratio Rank: 57
IMCB Omega Ratio Rank: 54
IMCB Calmar Ratio Rank: 61
IMCB Martin Ratio Rank: 66

SIZE

SIZE Risk / Return Rank: 48
SIZE Sharpe Ratio Rank: 44
SIZE Sortino Ratio Rank: 46
SIZE Omega Ratio Rank: 43
SIZE Calmar Ratio Rank: 50
SIZE Martin Ratio Rank: 55

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.

IMCB vs. SIZE - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Morningstar Mid-Cap ETF (IMCB) and iShares MSCI USA Size Factor ETF (SIZE). 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.

	IMCB	SIZE	Difference
Sharpe ratio Return per unit of total volatility	1.94	1.58	+0.36
Sortino ratio Return per unit of downside risk	2.75	2.32	+0.42
Omega ratio Gain probability vs. loss probability	1.34	1.28	+0.06
Calmar ratio Return relative to maximum drawdown	3.08	2.51	+0.58
Martin ratio Return relative to average drawdown	12.25	9.77	+2.47
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

IMCB vs. SIZE - Sharpe Ratio Comparison

The current IMCB Sharpe Ratio is 1.94, which is comparable to the SIZE Sharpe Ratio of 1.58. The chart below compares the historical Sharpe Ratios of IMCB and SIZE, 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

	IMCB	SIZE	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.94	1.58	+0.36
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.51	0.48	+0.03
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.58	0.64	-0.06
Sharpe Ratio (All Time) Calculated using the full available price history	0.50	0.69	-0.18

Drawdowns

IMCB vs. SIZE - Drawdown Comparison

The maximum IMCB drawdown since its inception was -58.80%, which is greater than SIZE's maximum drawdown of -39.15%. Use the drawdown chart below to compare losses from any high point for IMCB and SIZE.

Drawdown Indicators

	IMCB	SIZE	Difference
Max Drawdown Largest peak-to-trough decline	-58.80%	-39.15%	-19.65%
Max Drawdown (1Y) Largest decline over 1 year	-8.05%	-7.97%	-0.08%
Max Drawdown (3Y) Largest decline over 3 years	-19.80%	-18.71%	-1.09%
Max Drawdown (5Y) Largest decline over 5 years	-25.15%	-24.03%	-1.12%
Max Drawdown (10Y) Largest decline over 10 years	-40.99%	-39.15%	-1.84%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-7.73%	-4.19%	-3.54%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.03%	2.04%	-0.01%

Volatility

IMCB vs. SIZE - Volatility Comparison

iShares Morningstar Mid-Cap ETF (IMCB) has a higher volatility of 3.37% compared to iShares MSCI USA Size Factor ETF (SIZE) at 3.13%. This indicates that IMCB's price experiences larger fluctuations and is considered to be riskier than SIZE based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IMCB	SIZE	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.37%	3.13%	+0.24%
Volatility (6M) Calculated over the trailing 6-month period	9.61%	9.53%	+0.08%
Volatility (1Y) Calculated over the trailing 1-year period	12.75%	12.71%	+0.04%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.57%	17.39%	+0.18%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.65%	18.69%	+0.96%

IMCB vs. SIZE - Expense Ratio Comparison

IMCB has a 0.04% expense ratio, which is lower than SIZE's 0.15% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

IMCB vs. SIZE - Dividend Comparison

IMCB's dividend yield for the trailing twelve months is around 1.21%, less than SIZE's 1.41% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IMCB iShares Morningstar Mid-Cap ETF	1.21%	1.42%	1.43%	1.55%	1.70%	1.08%	1.12%	1.32%	1.80%	1.31%	1.79%	1.47%
SIZE iShares MSCI USA Size Factor ETF	1.41%	1.50%	1.53%	1.42%	1.59%	1.19%	1.43%	1.35%	2.43%	1.58%	1.88%	1.95%

Frequently Asked Questions

Can I hold both IMCB and SIZE in my portfolio?

With a correlation of 0.95, IMCB and SIZE 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, IMCB or SIZE?

IMCB has higher volatility (3.37%) compared to SIZE (3.13%). In terms of maximum drawdown, IMCB dropped -58.80% vs SIZE's -39.15%.

Which ETF is better, IMCB or SIZE?

On 10-year performance, SIZE leads with 11.83% vs 11.35% for IMCB. On fees, IMCB is cheaper at 0.04% per year. On volatility, SIZE has been the lower-risk option at 3.13%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, IMCB or SIZE?

Over the 10-year period, SIZE has performed better with a 11.83% return vs 11.35%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, IMCB or SIZE?

IMCB is cheaper with a 0.04% expense ratio, compared with 0.15% for SIZE.

Which ETF pays a higher dividend yield, IMCB or SIZE?

SIZE has the higher dividend yield at 1.41%, compared with 1.21% for IMCB.

What is the main difference between IMCB and SIZE?

IMCB tracks IMCB-US - Morningstar U.S. Mid Cap Index, while SIZE tracks MSCI USA Low Size Index. Their fees differ too: 0.04% for IMCB and 0.15% for SIZE.

Which has better risk-adjusted returns?

IMCB currently has the higher Sharpe Ratio (1.94 vs 1.58), 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.