PLFIX vs. MIEYX

Last updated Jun 4, 2026

PLFIX (Principal Large Cap S&P 500 Index Fund Institutional) and MIEYX (MM S&P 500 Index Fund) are both S&P 500 funds tracking the S&P 500 Index, from Principal and MassMutual respectively. Both are passively managed. Over the past 10 years, PLFIX returned 15.64%/yr vs 14.60%/yr for MIEYX. With a 0.99 correlation, they move nearly in lockstep. PLFIX charges 0.11%/yr vs 0.46%/yr for MIEYX.

Performance

PLFIX vs. MIEYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Principal Large Cap S&P 500 Index Fund Institutional (PLFIX) and MM S&P 500 Index Fund (MIEYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both stocks are quite close, with PLFIX having a 11.68% return and MIEYX slightly lower at 11.45%. Over the past 10 years, PLFIX has outperformed MIEYX with an annualized return of 15.64%, while MIEYX has yielded a comparatively lower 14.60% annualized return.

PLFIX

• 1D: 0.14%
• 1M: 5.79%
• YTD: 11.68%
• 6M: 11.75%
• 1Y: 28.92%
• 3Y*: 23.21%
• 5Y*: 14.45%
• 10Y*: 15.64%

MIEYX

• 1D: 0.13%
• 1M: 5.77%
• YTD: 11.45%
• 6M: 11.46%
• 1Y: 28.32%
• 3Y*: 22.16%
• 5Y*: 13.68%
• 10Y*: 14.60%

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

PLFIX vs. MIEYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PLFIX Principal Large Cap S&P 500 Index Fund Institutional	11.68%	17.77%	26.77%	26.00%	-18.21%	28.25%	18.11%	31.35%	-4.66%	21.65%
MIEYX MM S&P 500 Index Fund	11.45%	17.27%	24.36%	25.76%	-18.63%	28.02%	17.87%	30.98%	-5.26%	18.90%

Correlation

The correlation between PLFIX and MIEYX is 1.00 - 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	1.00
Correlation (3Y) Calculated over the trailing 3-year period	0.98
Correlation (5Y) Calculated over the trailing 5-year period	0.99
Correlation (10Y) Calculated over the trailing 10-year period	0.98
Correlation (All Time) Calculated using the full available price history since Mar 1, 2001	0.99

The correlation between PLFIX and MIEYX has been stable across timeframes, ranging from 0.98 to 1.00 - a consistent structural relationship.

Return for Risk

PLFIX vs. MIEYX — Risk / Return Rank

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

PLFIX

PLFIX Risk / Return Rank: 73
PLFIX Sharpe Ratio Rank: 75
PLFIX Sortino Ratio Rank: 67
PLFIX Omega Ratio Rank: 68
PLFIX Calmar Ratio Rank: 73
PLFIX Martin Ratio Rank: 83

MIEYX

MIEYX Risk / Return Rank: 70
MIEYX Sharpe Ratio Rank: 72
MIEYX Sortino Ratio Rank: 64
MIEYX Omega Ratio Rank: 64
MIEYX Calmar Ratio Rank: 71
MIEYX Martin Ratio Rank: 81

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.

PLFIX vs. MIEYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Principal Large Cap S&P 500 Index Fund Institutional (PLFIX) and MM S&P 500 Index Fund (MIEYX). 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.

	PLFIX	MIEYX	Difference
Sharpe ratio: Return per unit of total volatility	2.52	2.46	+0.05
Sortino ratio: Return per unit of downside risk	3.42	3.34	+0.08
Omega ratio: Gain probability vs. loss probability	1.46	1.45	+0.01
Calmar ratio: Return relative to maximum drawdown	3.34	3.28	+0.06
Martin ratio: Return relative to average drawdown	15.63	15.26	+0.37
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

PLFIX vs. MIEYX - Sharpe Ratio Comparison

The current PLFIX Sharpe Ratio is 2.52, which is comparable to the MIEYX Sharpe Ratio of 2.46. The chart below compares the historical Sharpe Ratios of PLFIX and MIEYX, 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

	PLFIX	MIEYX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.52	2.46	+0.05
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.86	0.54	+0.32
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.90	0.65	+0.25
Sharpe Ratio (All Time) Calculated using the full available price history	0.49	0.40	+0.09

Drawdowns

PLFIX vs. MIEYX - Drawdown Comparison

The maximum PLFIX drawdown since its inception was -55.28%, roughly equal to the maximum MIEYX drawdown of -55.63%. Use the drawdown chart below to compare losses from any high point for PLFIX and MIEYX.

Drawdown Indicators

	PLFIX	MIEYX	Difference
Max Drawdown Largest peak-to-trough decline	-55.28%	-55.63%	+0.35%
Max Drawdown (1Y) Largest decline over 1 year	-8.90%	-8.92%	+0.02%
Max Drawdown (3Y) Largest decline over 3 years	-18.77%	-36.63%	+17.86%
Max Drawdown (5Y) Largest decline over 5 years	-24.58%	-36.63%	+12.05%
Max Drawdown (10Y) Largest decline over 10 years	-33.77%	-36.63%	+2.86%
Current Drawdown Current decline from peak	0.00%	-2.43%	+2.43%
Average Drawdown Average peak-to-trough decline	-8.86%	-12.57%	+3.71%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.90%	1.91%	-0.01%

Volatility

PLFIX vs. MIEYX - Volatility Comparison

Principal Large Cap S&P 500 Index Fund Institutional (PLFIX) and MM S&P 500 Index Fund (MIEYX) have volatilities of 2.82% and 2.84%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PLFIX	MIEYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.82%	2.84%	-0.02%
Volatility (6M) Calculated over the trailing 6-month period	8.96%	8.99%	-0.03%
Volatility (1Y) Calculated over the trailing 1-year period	11.84%	11.89%	-0.05%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.91%	25.50%	-8.59%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.52%	22.57%	-5.05%

PLFIX vs. MIEYX - Expense Ratio Comparison

PLFIX has a 0.11% expense ratio, which is lower than MIEYX's 0.46% expense ratio.

Dividends

PLFIX vs. MIEYX - Dividend Comparison

PLFIX's dividend yield for the trailing twelve months is around 2.64%, less than MIEYX's 15.82% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MIEYX MM S&P 500 Index Fund	15.82%	17.63%	32.89%	7.13%	33.24%	13.29%	16.29%	6.38%	19.14%	21.81%	4.19%	2.29%
PLFIX Principal Large Cap S&P 500 Index Fund Institutional	2.64%	2.95%	4.28%	4.13%	2.96%	13.60%	7.57%	3.83%	7.52%	7.01%	3.23%	2.69%

Frequently Asked Questions

Can I hold both PLFIX and MIEYX in my portfolio?

With a correlation of 1.00, PLFIX and MIEYX 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, PLFIX or MIEYX?

MIEYX has higher volatility (2.84%) compared to PLFIX (2.82%). In terms of maximum drawdown, PLFIX dropped -55.28% vs MIEYX's -55.63%.

Which has better risk-adjusted returns?

PLFIX currently has the higher Sharpe Ratio (2.52 vs 2.46), 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.