MDIIX vs. BDBKX

Last updated Jun 23, 2026

MDIIX (iShares MSCI EAFE International Index Fund) and BDBKX (iShares Russell 2000 Small-Cap Index Fund Class K) are both mutual funds - MDIIX is a Foreign Large Cap Equities fund tracking the MSCI EAFE Index (Net), while BDBKX is a Small Cap Blend Equities fund tracking the Russell 2000 Index. Both are passively managed. Over the past 10 years, MDIIX returned 9.34%/yr vs 11.42%/yr for BDBKX. A 0.72 correlation means they provide meaningful diversification when combined. MDIIX charges 0.35%/yr vs 0.07%/yr for BDBKX.

Performance

MDIIX vs. BDBKX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares MSCI EAFE International Index Fund (MDIIX) and iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MDIIX achieves a 10.52% return, which is significantly lower than BDBKX's 20.72% return. Over the past 10 years, MDIIX has underperformed BDBKX with an annualized return of 9.34%, while BDBKX has yielded a comparatively higher 11.42% annualized return.

MDIIX

• 1D: 0.81%
• 1M: 1.97%
• YTD: 10.52%
• 6M: 10.93%
• 1Y: 25.09%
• 3Y*: 16.04%
• 5Y*: 9.19%
• 10Y*: 9.34%

BDBKX

• 1D: 2.15%
• 1M: 3.99%
• YTD: 20.72%
• 6M: 17.17%
• 1Y: 43.01%
• 3Y*: 18.28%
• 5Y*: 7.35%
• 10Y*: 11.42%

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

MDIIX vs. BDBKX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MDIIX iShares MSCI EAFE International Index Fund	10.52%	31.36%	3.36%	18.04%	-14.33%	10.98%	7.68%	21.55%	-13.62%	24.84%
BDBKX iShares Russell 2000 Small-Cap Index Fund Class K	20.72%	12.81%	11.40%	17.04%	-20.32%	14.59%	20.02%	25.66%	-11.01%	14.71%

Correlation

The correlation between MDIIX and BDBKX is 0.72, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.72
Correlation (3Y) Calculated over the trailing 3-year period	0.70
Correlation (5Y) Calculated over the trailing 5-year period	0.72
Correlation (10Y) Calculated over the trailing 10-year period	0.71
Correlation (All Time) Calculated using the full available price history since Mar 31, 2011	0.72

The correlation between MDIIX and BDBKX has been stable across timeframes, ranging from 0.70 to 0.72 - a consistent structural relationship.

Return for Risk

MDIIX vs. BDBKX — Risk / Return Rank

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

MDIIX

MDIIX Risk / Return Rank: 35
MDIIX Sharpe Ratio Rank: 34
MDIIX Sortino Ratio Rank: 33
MDIIX Omega Ratio Rank: 33
MDIIX Calmar Ratio Rank: 35
MDIIX Martin Ratio Rank: 39

BDBKX

BDBKX Risk / Return Rank: 69
BDBKX Sharpe Ratio Rank: 66
BDBKX Sortino Ratio Rank: 61
BDBKX Omega Ratio Rank: 50
BDBKX Calmar Ratio Rank: 86
BDBKX Martin Ratio Rank: 80

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.

MDIIX vs. BDBKX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares MSCI EAFE International Index Fund (MDIIX) and iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX). 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.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	MDIIX	BDBKX	Difference
Sharpe ratio: Return per unit of total volatility	1.56	2.19	-0.62
Sortino ratio: Return per unit of downside risk	2.23	2.99	-0.76
Omega ratio: Gain probability vs. loss probability	1.28	1.36	-0.07
Calmar ratio: Return relative to maximum drawdown	2.14	3.92	-1.78
Martin ratio: Return relative to average drawdown	7.97	13.86	-5.89

MDIIX vs. BDBKX - Sharpe Ratio Comparison

The current MDIIX Sharpe Ratio is 1.56, which is comparable to the BDBKX Sharpe Ratio of 2.19. The chart below compares the historical Sharpe Ratios of MDIIX and BDBKX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

MDIIX vs. BDBKX - Drawdown Comparison

The maximum MDIIX drawdown since its inception was -61.26%, which is greater than BDBKX's maximum drawdown of -41.66%. Use the drawdown chart below to compare losses from any high point for MDIIX and BDBKX.

Drawdown Indicators

	MDIIX	BDBKX	Difference
Max Drawdown Largest peak-to-trough decline	-61.26%	-41.66%	-19.60%
Max Drawdown (1Y) Largest decline over 1 year	-11.32%	-10.97%	-0.35%
Max Drawdown (3Y) Largest decline over 3 years	-13.67%	-27.53%	+13.86%
Max Drawdown (5Y) Largest decline over 5 years	-29.43%	-31.96%	+2.53%
Max Drawdown (10Y) Largest decline over 10 years	-34.34%	-41.66%	+7.32%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-15.54%	-8.72%	-6.82%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.03%	3.09%	-0.06%

Volatility

MDIIX vs. BDBKX - Volatility Comparison

The current volatility for iShares MSCI EAFE International Index Fund (MDIIX) is 4.95%, while iShares Russell 2000 Small-Cap Index Fund Class K (BDBKX) has a volatility of 6.77%. This indicates that MDIIX experiences smaller price fluctuations and is considered to be less risky than BDBKX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MDIIX	BDBKX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.95%	6.77%	-1.82%
Volatility (6M) Calculated over the trailing 6-month period	12.85%	14.33%	-1.48%
Volatility (1Y) Calculated over the trailing 1-year period	15.49%	19.66%	-4.17%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.25%	23.26%	-7.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.65%	23.76%	-7.11%

MDIIX vs. BDBKX - Expense Ratio Comparison

MDIIX has a 0.35% expense ratio, which is higher than BDBKX's 0.07% expense ratio.

Dividends

MDIIX vs. BDBKX - Dividend Comparison

MDIIX's dividend yield for the trailing twelve months is around 3.16%, more than BDBKX's 2.63% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BDBKX iShares Russell 2000 Small-Cap Index Fund Class K	2.63%	3.17%	4.84%	2.96%	1.76%	7.67%	1.45%	3.47%	4.29%	3.18%	4.62%	3.64%
MDIIX iShares MSCI EAFE International Index Fund	3.16%	3.49%	3.15%	2.94%	2.52%	2.78%	1.72%	3.05%	4.24%	2.21%	2.60%	1.94%

Frequently Asked Questions

Can I hold both MDIIX and BDBKX in my portfolio?

MDIIX and BDBKX have a correlation of 0.72, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MDIIX or BDBKX?

BDBKX has higher volatility (6.77%) compared to MDIIX (4.95%). In terms of maximum drawdown, MDIIX dropped -61.26% vs BDBKX's -41.66%.

Which has better risk-adjusted returns?

BDBKX currently has the higher Sharpe Ratio (2.19 vs 1.56), 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.