THCGX vs. ACIHX

Last updated Jun 23, 2026

THCGX (Thornburg Small/Mid Cap Growth Fund) and ACIHX (American Century Growth Fund G Class) are both Large Cap Growth Equities funds. Over the past 3 years, THCGX returned 13.36%/yr vs 20.56%/yr for ACIHX. A 0.79 correlation means they provide meaningful diversification when combined. THCGX charges 1.31%/yr vs 0.01%/yr for ACIHX.

Performance

THCGX vs. ACIHX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Thornburg Small/Mid Cap Growth Fund (THCGX) 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, THCGX achieves a 12.03% return, which is significantly higher than ACIHX's 4.95% return.

THCGX

• 1D: 1.62%
• 1M: 3.45%
• YTD: 12.03%
• 6M: 7.87%
• 1Y: 25.32%
• 3Y*: 13.36%
• 5Y*: 1.30%
• 10Y*: 9.25%

ACIHX

• 1D: 1.47%
• 1M: -0.26%
• YTD: 4.95%
• 6M: 4.49%
• 1Y: 23.59%
• 3Y*: 20.56%
• 5Y*: —
• 10Y*: —

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

THCGX vs. ACIHX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022
THCGX Thornburg Small/Mid Cap Growth Fund	12.03%	4.31%	19.67%	19.56%	-3.51%
ACIHX American Century Growth Fund G Class	4.95%	16.26%	27.35%	44.64%	-6.24%

Correlation

The correlation between THCGX and ACIHX is 0.74, 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	0.74
Correlation (3Y) Calculated over the trailing 3-year period	0.75
Correlation (All Time) Calculated using the full available price history since May 16, 2022	0.79

The correlation between THCGX and ACIHX has been stable across timeframes, ranging from 0.74 to 0.79 - a consistent structural relationship.

Return for Risk

THCGX vs. ACIHX — Risk / Return Rank

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

THCGX

THCGX Risk / Return Rank: 22
THCGX Sharpe Ratio Rank: 22
THCGX Sortino Ratio Rank: 22
THCGX Omega Ratio Rank: 20
THCGX Calmar Ratio Rank: 22
THCGX Martin Ratio Rank: 23

ACIHX

ACIHX Risk / Return Rank: 22
ACIHX Sharpe Ratio Rank: 27
ACIHX Sortino Ratio Rank: 24
ACIHX Omega Ratio Rank: 25
ACIHX Calmar Ratio Rank: 17
ACIHX Martin Ratio Rank: 19

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.

THCGX vs. ACIHX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Thornburg Small/Mid Cap Growth Fund (THCGX) 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.

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.

	THCGX	ACIHX	Difference
Sharpe ratio: Return per unit of total volatility	1.25	1.38	-0.13
Sortino ratio: Return per unit of downside risk	1.80	1.91	-0.11
Omega ratio: Gain probability vs. loss probability	1.22	1.24	-0.03
Calmar ratio: Return relative to maximum drawdown	1.62	1.39	+0.23
Martin ratio: Return relative to average drawdown	5.27	4.58	+0.70

THCGX vs. ACIHX - Sharpe Ratio Comparison

The current THCGX Sharpe Ratio is 1.25, which is comparable to the ACIHX Sharpe Ratio of 1.38. The chart below compares the historical Sharpe Ratios of THCGX 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.

Drawdowns

THCGX vs. ACIHX - Drawdown Comparison

The maximum THCGX drawdown since its inception was -63.67%, which is greater than ACIHX's maximum drawdown of -24.00%. Use the drawdown chart below to compare losses from any high point for THCGX and ACIHX.

Drawdown Indicators

	THCGX	ACIHX	Difference
Max Drawdown Largest peak-to-trough decline	-63.67%	-24.00%	-39.67%
Max Drawdown (1Y) Largest decline over 1 year	-15.53%	-16.40%	+0.87%
Max Drawdown (3Y) Largest decline over 3 years	-30.25%	-24.00%	-6.25%
Max Drawdown (5Y) Largest decline over 5 years	-63.67%	—	—
Max Drawdown (10Y) Largest decline over 10 years	-63.67%	—	—
Current Drawdown Current decline from peak	-33.67%	-4.16%	-29.51%
Average Drawdown Average peak-to-trough decline	-21.24%	-4.88%	-16.36%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.77%	4.98%	-0.21%

Volatility

THCGX vs. ACIHX - Volatility Comparison

Thornburg Small/Mid Cap Growth Fund (THCGX) and American Century Growth Fund G Class (ACIHX) have volatilities of 6.14% and 6.36%, 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

	THCGX	ACIHX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.14%	6.36%	-0.22%
Volatility (6M) Calculated over the trailing 6-month period	14.70%	13.07%	+1.63%
Volatility (1Y) Calculated over the trailing 1-year period	20.10%	16.53%	+3.57%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	36.99%	21.11%	+15.88%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	30.18%	21.11%	+9.07%

THCGX vs. ACIHX - Expense Ratio Comparison

THCGX has a 1.31% expense ratio, which is higher than ACIHX's 0.01% expense ratio.

Dividends

THCGX vs. ACIHX - Dividend Comparison

THCGX has not paid dividends to shareholders, while ACIHX's dividend yield for the trailing twelve months is around 15.20%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019
ACIHX American Century Growth Fund G Class	15.20%	15.95%	5.65%	4.61%	2.86%	0.00%	0.00%	0.00%
THCGX Thornburg Small/Mid Cap Growth Fund	0.00%	0.00%	0.00%	0.00%	0.00%	54.25%	6.23%	9.32%

Frequently Asked Questions

Can I hold both THCGX and ACIHX in my portfolio?

THCGX and ACIHX have a correlation of 0.74, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, THCGX or ACIHX?

ACIHX has higher volatility (6.36%) compared to THCGX (6.14%). In terms of maximum drawdown, THCGX dropped -63.67% vs ACIHX's -24.00%.

Which has better risk-adjusted returns?

ACIHX currently has the higher Sharpe Ratio (1.38 vs 1.25), 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.