FMDGX vs. VOO

Last updated Jun 24, 2026

FMDGX (Fidelity Mid Cap Growth Index Fund) and VOO (Vanguard S&P 500 ETF) are both funds - FMDGX is a Mid Cap Growth Equities fund tracking the Russell Midcap Growth Index, while VOO is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 5 years, FMDGX returned 5.63%/yr vs 13.13%/yr for VOO. Their correlation of 0.87 suggests significant overlap in exposure. FMDGX charges 0.05%/yr vs 0.03%/yr for VOO.

Performance

FMDGX vs. VOO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Mid Cap Growth Index Fund (FMDGX) and Vanguard S&P 500 ETF (VOO). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FMDGX achieves a 3.82% return, which is significantly lower than VOO's 8.19% return.

FMDGX

• 1D: -0.11%
• 1M: 1.82%
• YTD: 3.82%
• 6M: 1.82%
• 1Y: 5.26%
• 3Y*: 15.69%
• 5Y*: 5.63%
• 10Y*: —

VOO

• 1D: -1.42%
• 1M: -1.34%
• YTD: 8.19%
• 6M: 7.24%
• 1Y: 23.69%
• 3Y*: 20.78%
• 5Y*: 13.13%
• 10Y*: 15.61%

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

FMDGX vs. VOO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
FMDGX Fidelity Mid Cap Growth Index Fund	3.82%	8.60%	22.03%	25.79%	-26.67%	12.67%	34.84%	4.63%
VOO Vanguard S&P 500 ETF	8.19%	17.82%	24.98%	26.32%	-18.17%	28.79%	18.32%	8.49%

Correlation

The correlation between FMDGX and VOO is 0.81, 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	0.81
Correlation (3Y) Calculated over the trailing 3-year period	0.85
Correlation (5Y) Calculated over the trailing 5-year period	0.88
Correlation (All Time) Calculated using the full available price history since Jul 17, 2019	0.87

The correlation between FMDGX and VOO has been stable across timeframes, ranging from 0.81 to 0.88 - a consistent structural relationship.

Return for Risk

FMDGX vs. VOO — Risk / Return Rank

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

FMDGX

FMDGX Risk / Return Rank: 5
FMDGX Sharpe Ratio Rank: 5
FMDGX Sortino Ratio Rank: 5
FMDGX Omega Ratio Rank: 5
FMDGX Calmar Ratio Rank: 5
FMDGX Martin Ratio Rank: 6

VOO

VOO Risk / Return Rank: 59
VOO Sharpe Ratio Rank: 59
VOO Sortino Ratio Rank: 56
VOO Omega Ratio Rank: 58
VOO Calmar Ratio Rank: 56
VOO Martin Ratio Rank: 67

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.

FMDGX vs. VOO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mid Cap Growth Index Fund (FMDGX) and Vanguard S&P 500 ETF (VOO). 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.

	FMDGX	VOO	Difference
Sharpe ratio: Return per unit of total volatility	0.36	1.91	-1.56
Sortino ratio: Return per unit of downside risk	0.62	2.60	-1.98
Omega ratio: Gain probability vs. loss probability	1.07	1.35	-0.28
Calmar ratio: Return relative to maximum drawdown	0.42	2.67	-2.26
Martin ratio: Return relative to average drawdown	1.20	11.96	-10.76

FMDGX vs. VOO - Sharpe Ratio Comparison

The current FMDGX Sharpe Ratio is 0.36, which is lower than the VOO Sharpe Ratio of 1.91. The chart below compares the historical Sharpe Ratios of FMDGX and VOO, 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

FMDGX vs. VOO - Drawdown Comparison

The maximum FMDGX drawdown since its inception was -38.59%, which is greater than VOO's maximum drawdown of -33.99%. Use the drawdown chart below to compare losses from any high point for FMDGX and VOO.

Drawdown Indicators

	FMDGX	VOO	Difference
Max Drawdown Largest peak-to-trough decline	-38.59%	-33.99%	-4.60%
Max Drawdown (1Y) Largest decline over 1 year	-14.75%	-8.90%	-5.85%
Max Drawdown (3Y) Largest decline over 3 years	-25.30%	-18.69%	-6.61%
Max Drawdown (5Y) Largest decline over 5 years	-38.59%	-24.52%	-14.07%
Max Drawdown (10Y) Largest decline over 10 years	—	-33.99%	—
Current Drawdown Current decline from peak	-2.08%	-3.14%	+1.06%
Average Drawdown Average peak-to-trough decline	-11.14%	-3.68%	-7.46%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.09%	1.99%	+3.10%

Volatility

FMDGX vs. VOO - Volatility Comparison

Fidelity Mid Cap Growth Index Fund (FMDGX) has a higher volatility of 5.70% compared to Vanguard S&P 500 ETF (VOO) at 4.83%. This indicates that FMDGX's price experiences larger fluctuations and is considered to be riskier than VOO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FMDGX	VOO	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.70%	4.83%	+0.87%
Volatility (6M) Calculated over the trailing 6-month period	13.38%	9.82%	+3.56%
Volatility (1Y) Calculated over the trailing 1-year period	17.07%	12.46%	+4.61%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.45%	16.91%	+5.54%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	24.30%	18.02%	+6.28%

FMDGX vs. VOO - Expense Ratio Comparison

FMDGX has a 0.05% expense ratio, which is higher than VOO's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

FMDGX vs. VOO - Dividend Comparison

FMDGX's dividend yield for the trailing twelve months is around 1.79%, more than VOO's 1.05% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FMDGX Fidelity Mid Cap Growth Index Fund	1.79%	1.85%	0.47%	0.63%	0.81%	6.43%	0.36%	0.29%	0.00%	0.00%	0.00%	0.00%
VOO Vanguard S&P 500 ETF	1.05%	1.13%	1.24%	1.46%	1.69%	1.25%	1.54%	1.88%	2.06%	1.78%	2.02%	2.10%

Frequently Asked Questions

Can I hold both FMDGX and VOO in my portfolio?

FMDGX and VOO have a correlation of 0.81, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FMDGX or VOO?

FMDGX has higher volatility (5.70%) compared to VOO (4.83%). In terms of maximum drawdown, FMDGX dropped -38.59% vs VOO's -33.99%.

Which has better risk-adjusted returns?

VOO currently has the higher Sharpe Ratio (1.91 vs 0.36), 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.