PIDIX vs. DFAI

Last updated Jun 24, 2026

PIDIX (Principal International Equity Index Fund) and DFAI (Dimensional International Core Equity Market ETF) are both Foreign Large Cap Equities funds. Over the past 5 years, PIDIX returned 9.29%/yr vs 9.35%/yr for DFAI. With a 0.98 correlation, they move nearly in lockstep. PIDIX charges 0.32%/yr vs 0.18%/yr for DFAI.

Performance

PIDIX vs. DFAI - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Principal International Equity Index Fund (PIDIX) and Dimensional International Core Equity Market ETF (DFAI). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PIDIX achieves a 10.72% return, which is significantly higher than DFAI's 7.50% return.

PIDIX

• 1D: 0.13%
• 1M: 2.12%
• YTD: 10.72%
• 6M: 10.19%
• 1Y: 24.17%
• 3Y*: 17.74%
• 5Y*: 9.29%
• 10Y*: 10.03%

DFAI

• 1D: -2.83%
• 1M: -1.64%
• YTD: 7.50%
• 6M: 6.97%
• 1Y: 23.12%
• 3Y*: 17.77%
• 5Y*: 9.35%
• 10Y*: —

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

PIDIX vs. DFAI - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
PIDIX Principal International Equity Index Fund	10.72%	31.07%	4.72%	17.87%	-14.43%	11.07%	5.68%
DFAI Dimensional International Core Equity Market ETF	7.50%	34.04%	4.68%	17.60%	-12.95%	13.86%	5.34%

Correlation

The correlation between PIDIX and DFAI is 0.96 - 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	0.96
Correlation (3Y) Calculated over the trailing 3-year period	0.97
Correlation (5Y) Calculated over the trailing 5-year period	0.98
Correlation (All Time) Calculated using the full available price history since Nov 18, 2020	0.98

The correlation between PIDIX and DFAI has been stable across timeframes, ranging from 0.96 to 0.98 - a consistent structural relationship.

Return for Risk

PIDIX vs. DFAI — Risk / Return Rank

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

PIDIX

PIDIX Risk / Return Rank: 37
PIDIX Sharpe Ratio Rank: 37
PIDIX Sortino Ratio Rank: 36
PIDIX Omega Ratio Rank: 36
PIDIX Calmar Ratio Rank: 39
PIDIX Martin Ratio Rank: 40

DFAI

DFAI Risk / Return Rank: 47
DFAI Sharpe Ratio Rank: 47
DFAI Sortino Ratio Rank: 46
DFAI Omega Ratio Rank: 46
DFAI Calmar Ratio Rank: 44
DFAI Martin Ratio Rank: 50

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.

PIDIX vs. DFAI - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Principal International Equity Index Fund (PIDIX) and Dimensional International Core Equity Market ETF (DFAI). 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.

	PIDIX	DFAI	Difference
Sharpe ratio: Return per unit of total volatility	1.63	1.57	+0.05
Sortino ratio: Return per unit of downside risk	2.31	2.21	+0.10
Omega ratio: Gain probability vs. loss probability	1.29	1.29	+0.01
Calmar ratio: Return relative to maximum drawdown	2.23	2.12	+0.11
Martin ratio: Return relative to average drawdown	8.33	8.25	+0.08

PIDIX vs. DFAI - Sharpe Ratio Comparison

The current PIDIX Sharpe Ratio is 1.63, which is comparable to the DFAI Sharpe Ratio of 1.57. The chart below compares the historical Sharpe Ratios of PIDIX and DFAI, 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

PIDIX vs. DFAI - Drawdown Comparison

The maximum PIDIX drawdown since its inception was -34.13%, which is greater than DFAI's maximum drawdown of -27.44%. Use the drawdown chart below to compare losses from any high point for PIDIX and DFAI.

Drawdown Indicators

	PIDIX	DFAI	Difference
Max Drawdown Largest peak-to-trough decline	-34.13%	-27.44%	-6.69%
Max Drawdown (1Y) Largest decline over 1 year	-11.31%	-10.95%	-0.36%
Max Drawdown (3Y) Largest decline over 3 years	-13.59%	-13.25%	-0.34%
Max Drawdown (5Y) Largest decline over 5 years	-29.50%	-27.44%	-2.06%
Max Drawdown (10Y) Largest decline over 10 years	-34.13%	—	—
Current Drawdown Current decline from peak	0.00%	-3.10%	+3.10%
Average Drawdown Average peak-to-trough decline	-7.47%	-5.09%	-2.38%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.03%	2.81%	+0.22%

Volatility

PIDIX vs. DFAI - Volatility Comparison

The current volatility for Principal International Equity Index Fund (PIDIX) is 4.81%, while Dimensional International Core Equity Market ETF (DFAI) has a volatility of 5.38%. This indicates that PIDIX experiences smaller price fluctuations and is considered to be less risky than DFAI based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PIDIX	DFAI	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.81%	5.38%	-0.57%
Volatility (6M) Calculated over the trailing 6-month period	12.91%	12.60%	+0.31%
Volatility (1Y) Calculated over the trailing 1-year period	15.56%	14.77%	+0.79%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.26%	16.03%	+0.23%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.30%	15.77%	+0.53%

PIDIX vs. DFAI - Expense Ratio Comparison

PIDIX has a 0.32% expense ratio, which is higher than DFAI's 0.18% expense ratio.

Dividends

PIDIX vs. DFAI - Dividend Comparison

PIDIX's dividend yield for the trailing twelve months is around 3.10%, more than DFAI's 2.29% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
DFAI Dimensional International Core Equity Market ETF	2.29%	2.45%	2.72%	2.64%	2.72%	2.06%	0.09%	0.00%	0.00%	0.00%	0.00%	0.00%
PIDIX Principal International Equity Index Fund	3.10%	3.43%	5.85%	3.81%	2.82%	5.14%	2.34%	3.36%	3.91%	3.48%	2.82%	3.67%

Frequently Asked Questions

Can I hold both PIDIX and DFAI in my portfolio?

With a correlation of 0.96, PIDIX and DFAI 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, PIDIX or DFAI?

DFAI has higher volatility (5.38%) compared to PIDIX (4.81%). In terms of maximum drawdown, PIDIX dropped -34.13% vs DFAI's -27.44%.

Which has better risk-adjusted returns?

PIDIX currently has the higher Sharpe Ratio (1.63 vs 1.57), 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.