MDPIX vs. FZFLX

Last updated Jun 4, 2026

MDPIX (ProFunds Mid Cap Fund) and FZFLX (Fidelity SAI Small-Mid Cap 500 Index Fund) are both Mid Cap Blend Equities funds. Over the past 10 years, MDPIX returned 9.10%/yr vs 14.07%/yr for FZFLX. With a 0.96 correlation, they move nearly in lockstep. MDPIX charges 1.82%/yr vs 0.05%/yr for FZFLX.

Performance

MDPIX vs. FZFLX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in ProFunds Mid Cap Fund (MDPIX) and Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MDPIX achieves a 13.17% return, which is significantly lower than FZFLX's 33.04% return. Over the past 10 years, MDPIX has underperformed FZFLX with an annualized return of 9.10%, while FZFLX has yielded a comparatively higher 14.07% annualized return.

MDPIX

• 1D: 0.86%
• 1M: 3.79%
• YTD: 13.17%
• 6M: 13.24%
• 1Y: 23.44%
• 3Y*: 13.94%
• 5Y*: 6.16%
• 10Y*: 9.10%

FZFLX

• 1D: 1.53%
• 1M: 6.05%
• YTD: 33.04%
• 6M: 33.74%
• 1Y: 48.52%
• 3Y*: 24.40%
• 5Y*: 12.03%
• 10Y*: 14.07%

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

MDPIX vs. FZFLX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MDPIX ProFunds Mid Cap Fund	13.17%	5.68%	11.55%	14.16%	-14.81%	21.89%	11.24%	23.46%	-12.78%	14.18%
FZFLX Fidelity SAI Small-Mid Cap 500 Index Fund	33.04%	10.76%	15.52%	17.75%	-15.62%	20.40%	19.78%	31.96%	-9.25%	18.41%

Correlation

The correlation between MDPIX and FZFLX is 0.91, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.91
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.96
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Aug 21, 2015	0.96

The correlation between MDPIX and FZFLX has been stable across timeframes, ranging from 0.91 to 0.96 - a consistent structural relationship.

Return for Risk

MDPIX vs. FZFLX — Risk / Return Rank

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

MDPIX

MDPIX Risk / Return Rank: 39
MDPIX Sharpe Ratio Rank: 32
MDPIX Sortino Ratio Rank: 33
MDPIX Omega Ratio Rank: 30
MDPIX Calmar Ratio Rank: 53
MDPIX Martin Ratio Rank: 48

FZFLX

FZFLX Risk / Return Rank: 74
FZFLX Sharpe Ratio Rank: 71
FZFLX Sortino Ratio Rank: 58
FZFLX Omega Ratio Rank: 58
FZFLX Calmar Ratio Rank: 91
FZFLX Martin Ratio Rank: 93

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.

MDPIX vs. FZFLX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for ProFunds Mid Cap Fund (MDPIX) and Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX). 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.

	MDPIX	FZFLX	Difference
Sharpe ratio: Return per unit of total volatility	1.62	2.44	-0.82
Sortino ratio: Return per unit of downside risk	2.37	3.22	-0.85
Omega ratio: Gain probability vs. loss probability	1.29	1.42	-0.14
Calmar ratio: Return relative to maximum drawdown	2.78	4.77	-1.99
Martin ratio: Return relative to average drawdown	9.98	20.14	-10.16
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MDPIX vs. FZFLX - Sharpe Ratio Comparison

The current MDPIX Sharpe Ratio is 1.62, which is lower than the FZFLX Sharpe Ratio of 2.44. The chart below compares the historical Sharpe Ratios of MDPIX and FZFLX, 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

	MDPIX	FZFLX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.62	2.44	-0.82
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.31	0.57	-0.26
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.44	0.67	-0.23
Sharpe Ratio (All Time) Calculated using the full available price history	0.36	0.63	-0.27

Drawdowns

MDPIX vs. FZFLX - Drawdown Comparison

The maximum MDPIX drawdown since its inception was -57.32%, which is greater than FZFLX's maximum drawdown of -42.03%. Use the drawdown chart below to compare losses from any high point for MDPIX and FZFLX.

Drawdown Indicators

	MDPIX	FZFLX	Difference
Max Drawdown Largest peak-to-trough decline	-57.32%	-42.03%	-15.29%
Max Drawdown (1Y) Largest decline over 1 year	-9.02%	-10.68%	+1.66%
Max Drawdown (3Y) Largest decline over 3 years	-24.59%	-22.29%	-2.30%
Max Drawdown (5Y) Largest decline over 5 years	-24.86%	-24.77%	-0.09%
Max Drawdown (10Y) Largest decline over 10 years	-42.07%	-42.03%	-0.04%
Current Drawdown Current decline from peak	0.00%	-0.33%	+0.33%
Average Drawdown Average peak-to-trough decline	-8.69%	-5.74%	-2.95%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.51%	2.52%	-0.01%

Volatility

MDPIX vs. FZFLX - Volatility Comparison

The current volatility for ProFunds Mid Cap Fund (MDPIX) is 4.44%, while Fidelity SAI Small-Mid Cap 500 Index Fund (FZFLX) has a volatility of 7.41%. This indicates that MDPIX experiences smaller price fluctuations and is considered to be less risky than FZFLX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MDPIX	FZFLX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.44%	7.41%	-2.97%
Volatility (6M) Calculated over the trailing 6-month period	11.29%	17.71%	-6.42%
Volatility (1Y) Calculated over the trailing 1-year period	15.44%	20.84%	-5.40%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.72%	21.11%	-1.39%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.73%	21.11%	-0.38%

MDPIX vs. FZFLX - Expense Ratio Comparison

MDPIX has a 1.82% expense ratio, which is higher than FZFLX's 0.05% expense ratio.

Dividends

MDPIX vs. FZFLX - Dividend Comparison

MDPIX's dividend yield for the trailing twelve months is around 0.36%, less than FZFLX's 43.42% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FZFLX Fidelity SAI Small-Mid Cap 500 Index Fund	43.42%	57.77%	10.20%	2.35%	79.79%	50.77%	7.19%	6.49%	7.69%	1.68%	0.93%	0.67%
MDPIX ProFunds Mid Cap Fund	0.36%	0.41%	1.26%	0.00%	0.00%	1.79%	0.24%	5.00%	3.00%	7.60%	0.00%	0.05%

Frequently Asked Questions

Can I hold both MDPIX and FZFLX in my portfolio?

With a correlation of 0.91, MDPIX and FZFLX 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, MDPIX or FZFLX?

FZFLX has higher volatility (7.41%) compared to MDPIX (4.44%). In terms of maximum drawdown, MDPIX dropped -57.32% vs FZFLX's -42.03%.

Which has better risk-adjusted returns?

FZFLX currently has the higher Sharpe Ratio (2.44 vs 1.62), 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.