FUMIX vs. ACIHX

Last updated Jun 4, 2026

FUMIX (Fidelity SAI U.S. Momentum Index Fund) and ACIHX (American Century Growth Fund G Class) are both Large Cap Growth Equities funds. Over the past 3 years, FUMIX returned 32.20%/yr vs 23.07%/yr for ACIHX. Their correlation of 0.81 suggests significant overlap in exposure. FUMIX charges 0.11%/yr vs 0.01%/yr for ACIHX.

Performance

FUMIX vs. ACIHX - Performance Comparison

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

Returns By Period

In the year-to-date period, FUMIX achieves a 26.12% return, which is significantly higher than ACIHX's 8.95% return.

FUMIX

• 1D: 1.48%
• 1M: 12.10%
• YTD: 26.12%
• 6M: 26.26%
• 1Y: 33.30%
• 3Y*: 32.20%
• 5Y*: 17.10%
• 10Y*: —

ACIHX

• 1D: -0.51%
• 1M: 7.84%
• YTD: 8.95%
• 6M: 8.02%
• 1Y: 27.75%
• 3Y*: 23.07%
• 5Y*: —
• 10Y*: —

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

FUMIX vs. ACIHX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022
FUMIX Fidelity SAI U.S. Momentum Index Fund	26.12%	17.01%	33.39%	14.67%	4.20%
ACIHX American Century Growth Fund G Class	8.95%	16.26%	27.35%	44.64%	-6.24%

Correlation

The correlation between FUMIX and ACIHX is 0.79, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.79
Correlation (3Y) Calculated over the trailing 3-year period	0.84
Correlation (All Time) Calculated using the full available price history since May 17, 2022	0.81

The correlation between FUMIX and ACIHX has been stable across timeframes, ranging from 0.79 to 0.84 - a consistent structural relationship.

Return for Risk

FUMIX vs. ACIHX — Risk / Return Rank

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

FUMIX

FUMIX Risk / Return Rank: 55
FUMIX Sharpe Ratio Rank: 46
FUMIX Sortino Ratio Rank: 44
FUMIX Omega Ratio Rank: 45
FUMIX Calmar Ratio Rank: 65
FUMIX Martin Ratio Rank: 74

ACIHX

ACIHX Risk / Return Rank: 31
ACIHX Sharpe Ratio Rank: 40
ACIHX Sortino Ratio Rank: 36
ACIHX Omega Ratio Rank: 36
ACIHX Calmar Ratio Rank: 22
ACIHX Martin Ratio Rank: 23

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.

FUMIX vs. ACIHX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity SAI U.S. Momentum Index Fund (FUMIX) and American Century Growth Fund G Class (ACIHX). 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.

	FUMIX	ACIHX	Difference
Sharpe ratio: Return per unit of total volatility	1.99	1.83	+0.16
Sortino ratio: Return per unit of downside risk	2.79	2.48	+0.31
Omega ratio: Gain probability vs. loss probability	1.36	1.32	+0.04
Calmar ratio: Return relative to maximum drawdown	3.10	1.75	+1.35
Martin ratio: Return relative to average drawdown	14.10	5.88	+8.22
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FUMIX vs. ACIHX - Sharpe Ratio Comparison

The current FUMIX Sharpe Ratio is 1.99, which is comparable to the ACIHX Sharpe Ratio of 1.83. The chart below compares the historical Sharpe Ratios of FUMIX and ACIHX, 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

	FUMIX	ACIHX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.99	1.83	+0.16
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.81	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.81	1.02	-0.21

Drawdowns

FUMIX vs. ACIHX - Drawdown Comparison

The maximum FUMIX drawdown since its inception was -33.36%, which is greater than ACIHX's maximum drawdown of -24.00%. Use the drawdown chart below to compare losses from any high point for FUMIX and ACIHX.

Drawdown Indicators

	FUMIX	ACIHX	Difference
Max Drawdown Largest peak-to-trough decline	-33.36%	-24.00%	-9.36%
Max Drawdown (1Y) Largest decline over 1 year	-10.99%	-16.40%	+5.41%
Max Drawdown (3Y) Largest decline over 3 years	-19.90%	-24.00%	+4.10%
Max Drawdown (5Y) Largest decline over 5 years	-27.66%	—	—
Current Drawdown Current decline from peak	0.00%	-0.51%	+0.51%
Average Drawdown Average peak-to-trough decline	-6.32%	-4.89%	-1.43%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.41%	4.87%	-2.46%

Volatility

FUMIX vs. ACIHX - Volatility Comparison

Fidelity SAI U.S. Momentum Index Fund (FUMIX) has a higher volatility of 6.51% compared to American Century Growth Fund G Class (ACIHX) at 3.44%. This indicates that FUMIX's price experiences larger fluctuations and is considered to be riskier than ACIHX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FUMIX	ACIHX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.51%	3.44%	+3.07%
Volatility (6M) Calculated over the trailing 6-month period	14.70%	11.92%	+2.78%
Volatility (1Y) Calculated over the trailing 1-year period	17.12%	15.71%	+1.41%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.17%	21.05%	+0.12%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.77%	21.05%	+0.72%

FUMIX vs. ACIHX - Expense Ratio Comparison

FUMIX has a 0.11% expense ratio, which is higher than ACIHX's 0.01% 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

FUMIX vs. ACIHX - Dividend Comparison

FUMIX's dividend yield for the trailing twelve months is around 2.20%, less than ACIHX's 14.64% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017
ACIHX American Century Growth Fund G Class	14.64%	15.95%	5.65%	4.61%	2.86%	0.00%	0.00%	0.00%	0.00%	0.00%
FUMIX Fidelity SAI U.S. Momentum Index Fund	2.20%	2.77%	5.89%	18.09%	2.10%	20.67%	8.68%	2.09%	3.84%	0.88%

Frequently Asked Questions

Can I hold both FUMIX and ACIHX in my portfolio?

FUMIX and ACIHX have a correlation of 0.79, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FUMIX or ACIHX?

FUMIX has higher volatility (6.51%) compared to ACIHX (3.44%). In terms of maximum drawdown, FUMIX dropped -33.36% vs ACIHX's -24.00%.

Which has better risk-adjusted returns?

FUMIX currently has the higher Sharpe Ratio (1.99 vs 1.83), 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.