GFAFX vs. FUMIX

Last updated Jun 25, 2026

GFAFX (American Funds Growth Fund of America Class F-1) and FUMIX (Fidelity SAI U.S. Momentum Index Fund) are both Large Cap Growth Equities funds. Over the past 5 years, GFAFX returned 10.76%/yr vs 16.29%/yr for FUMIX. Their correlation of 0.88 suggests significant overlap in exposure. GFAFX charges 0.65%/yr vs 0.11%/yr for FUMIX.

Performance

GFAFX vs. FUMIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds Growth Fund of America Class F-1 (GFAFX) and Fidelity SAI U.S. Momentum Index Fund (FUMIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, GFAFX achieves a 6.33% return, which is significantly lower than FUMIX's 28.11% return.

GFAFX

• 1D: -2.17%
• 1M: -0.26%
• YTD: 6.33%
• 6M: 5.13%
• 1Y: 18.01%
• 3Y*: 22.97%
• 5Y*: 10.76%
• 10Y*: 15.96%

FUMIX

• 1D: -3.41%
• 1M: 5.91%
• YTD: 28.11%
• 6M: 25.67%
• 1Y: 34.10%
• 3Y*: 32.09%
• 5Y*: 16.29%
• 10Y*: —

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

GFAFX vs. FUMIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
GFAFX American Funds Growth Fund of America Class F-1	6.33%	19.66%	27.96%	37.15%	-30.78%	19.24%	37.78%	28.10%	-3.23%	20.09%
FUMIX Fidelity SAI U.S. Momentum Index Fund	28.11%	17.01%	33.39%	14.67%	-15.79%	22.56%	29.92%	24.16%	-1.41%	22.71%

Correlation

The correlation between GFAFX and FUMIX is 0.83, 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	0.83
Correlation (3Y) Calculated over the trailing 3-year period	0.88
Correlation (5Y) Calculated over the trailing 5-year period	0.87
Correlation (All Time) Calculated using the full available price history since Feb 9, 2017	0.88

The correlation between GFAFX and FUMIX has been stable across timeframes, ranging from 0.83 to 0.88 - a consistent structural relationship.

Return for Risk

GFAFX vs. FUMIX — Risk / Return Rank

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

GFAFX

GFAFX Risk / Return Rank: 24
GFAFX Sharpe Ratio Rank: 25
GFAFX Sortino Ratio Rank: 23
GFAFX Omega Ratio Rank: 25
GFAFX Calmar Ratio Rank: 21
GFAFX Martin Ratio Rank: 27

FUMIX

FUMIX Risk / Return Rank: 61
FUMIX Sharpe Ratio Rank: 50
FUMIX Sortino Ratio Rank: 46
FUMIX Omega Ratio Rank: 49
FUMIX Calmar Ratio Rank: 76
FUMIX Martin Ratio Rank: 84

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.

GFAFX vs. FUMIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds Growth Fund of America Class F-1 (GFAFX) and Fidelity SAI U.S. Momentum Index Fund (FUMIX). 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.

	GFAFX	FUMIX	Difference
Sharpe ratio: Return per unit of total volatility	1.23	1.91	-0.69
Sortino ratio: Return per unit of downside risk	1.72	2.62	-0.89
Omega ratio: Gain probability vs. loss probability	1.23	1.35	-0.12
Calmar ratio: Return relative to maximum drawdown	1.46	3.27	-1.81
Martin ratio: Return relative to average drawdown	5.57	14.59	-9.02

GFAFX vs. FUMIX - Sharpe Ratio Comparison

The current GFAFX Sharpe Ratio is 1.23, which is lower than the FUMIX Sharpe Ratio of 1.91. The chart below compares the historical Sharpe Ratios of GFAFX and FUMIX, 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

GFAFX vs. FUMIX - Drawdown Comparison

The maximum GFAFX drawdown since its inception was -51.87%, which is greater than FUMIX's maximum drawdown of -33.36%. Use the drawdown chart below to compare losses from any high point for GFAFX and FUMIX.

Drawdown Indicators

	GFAFX	FUMIX	Difference
Max Drawdown Largest peak-to-trough decline	-51.87%	-33.36%	-18.51%
Max Drawdown (1Y) Largest decline over 1 year	-13.79%	-10.99%	-2.80%
Max Drawdown (3Y) Largest decline over 3 years	-21.57%	-19.90%	-1.67%
Max Drawdown (5Y) Largest decline over 5 years	-36.41%	-27.66%	-8.75%
Max Drawdown (10Y) Largest decline over 10 years	-36.41%	—	—
Current Drawdown Current decline from peak	-3.71%	-3.41%	-0.30%
Average Drawdown Average peak-to-trough decline	-8.60%	-6.29%	-2.31%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.61%	2.45%	+1.16%

Volatility

GFAFX vs. FUMIX - Volatility Comparison

The current volatility for American Funds Growth Fund of America Class F-1 (GFAFX) is 7.15%, while Fidelity SAI U.S. Momentum Index Fund (FUMIX) has a volatility of 8.64%. This indicates that GFAFX experiences smaller price fluctuations and is considered to be less risky than FUMIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	GFAFX	FUMIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.15%	8.64%	-1.49%
Volatility (6M) Calculated over the trailing 6-month period	13.17%	16.40%	-3.23%
Volatility (1Y) Calculated over the trailing 1-year period	16.44%	18.81%	-2.37%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.45%	21.44%	-0.99%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.75%	21.86%	-2.11%

GFAFX vs. FUMIX - Expense Ratio Comparison

GFAFX has a 0.65% expense ratio, which is higher than FUMIX's 0.11% expense ratio.

Dividends

GFAFX vs. FUMIX - Dividend Comparison

GFAFX's dividend yield for the trailing twelve months is around 10.11%, more than FUMIX's 2.17% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FUMIX Fidelity SAI U.S. Momentum Index Fund	2.17%	2.77%	5.89%	18.09%	2.10%	20.67%	8.68%	2.09%	3.84%	0.88%	0.00%	0.00%
GFAFX American Funds Growth Fund of America Class F-1	10.11%	10.75%	9.01%	7.41%	4.02%	8.16%	4.28%	7.14%	11.96%	6.98%	6.60%	8.86%

Frequently Asked Questions

Can I hold both GFAFX and FUMIX in my portfolio?

GFAFX and FUMIX have a correlation of 0.83, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, GFAFX or FUMIX?

FUMIX has higher volatility (8.64%) compared to GFAFX (7.15%). In terms of maximum drawdown, GFAFX dropped -51.87% vs FUMIX's -33.36%.

Which has better risk-adjusted returns?

FUMIX currently has the higher Sharpe Ratio (1.91 vs 1.23), 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.