MGTIX vs. AGTHX

Last updated Jun 23, 2026

MGTIX (MFS Massachusetts Investors Growth Stock Fund) and AGTHX (American Funds The Growth Fund of America Class A) are both Large Cap Growth Equities funds. Over the past 10 years, MGTIX returned 14.66%/yr vs 16.02%/yr for AGTHX. Their correlation of 0.92 suggests significant overlap in exposure. MGTIX charges 0.45%/yr vs 0.59%/yr for AGTHX.

Performance

MGTIX vs. AGTHX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Massachusetts Investors Growth Stock Fund (MGTIX) and American Funds The Growth Fund of America Class A (AGTHX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MGTIX achieves a -2.91% return, which is significantly lower than AGTHX's 9.30% return. Over the past 10 years, MGTIX has underperformed AGTHX with an annualized return of 14.66%, while AGTHX has yielded a comparatively higher 16.02% annualized return.

MGTIX

• 1D: 0.98%
• 1M: -0.68%
• YTD: -2.91%
• 6M: -3.11%
• 1Y: 7.76%
• 3Y*: 13.61%
• 5Y*: 9.71%
• 10Y*: 14.66%

AGTHX

• 1D: 1.78%
• 1M: 2.49%
• YTD: 9.30%
• 6M: 8.68%
• 1Y: 24.65%
• 3Y*: 23.64%
• 5Y*: 11.98%
• 10Y*: 16.02%

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

MGTIX vs. AGTHX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MGTIX MFS Massachusetts Investors Growth Stock Fund	-2.91%	10.23%	27.38%	24.40%	-18.99%	26.41%	22.84%	40.17%	1.07%	28.97%
AGTHX American Funds The Growth Fund of America Class A	9.30%	19.73%	28.02%	37.22%	-30.75%	19.32%	37.83%	28.16%	-3.15%	26.14%

Correlation

The correlation between MGTIX and AGTHX is 0.84, 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	0.84
Correlation (3Y) Calculated over the trailing 3-year period	0.87
Correlation (5Y) Calculated over the trailing 5-year period	0.89
Correlation (10Y) Calculated over the trailing 10-year period	0.89
Correlation (All Time) Calculated using the full available price history since Dec 31, 1996	0.92

The correlation between MGTIX and AGTHX has been stable across timeframes, ranging from 0.84 to 0.92 - a consistent structural relationship.

Return for Risk

MGTIX vs. AGTHX — Risk / Return Rank

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

MGTIX

MGTIX Risk / Return Rank: 7
MGTIX Sharpe Ratio Rank: 7
MGTIX Sortino Ratio Rank: 7
MGTIX Omega Ratio Rank: 7
MGTIX Calmar Ratio Rank: 6
MGTIX Martin Ratio Rank: 7

AGTHX

AGTHX Risk / Return Rank: 30
AGTHX Sharpe Ratio Rank: 31
AGTHX Sortino Ratio Rank: 28
AGTHX Omega Ratio Rank: 31
AGTHX Calmar Ratio Rank: 26
AGTHX Martin Ratio Rank: 31

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.

MGTIX vs. AGTHX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Massachusetts Investors Growth Stock Fund (MGTIX) and American Funds The Growth Fund of America Class A (AGTHX). 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.

	MGTIX	AGTHX	Difference
Sharpe ratio: Return per unit of total volatility	0.56	1.49	-0.93
Sortino ratio: Return per unit of downside risk	0.85	2.06	-1.21
Omega ratio: Gain probability vs. loss probability	1.10	1.27	-0.17
Calmar ratio: Return relative to maximum drawdown	0.54	1.77	-1.23
Martin ratio: Return relative to average drawdown	1.74	6.75	-5.01

MGTIX vs. AGTHX - Sharpe Ratio Comparison

The current MGTIX Sharpe Ratio is 0.56, which is lower than the AGTHX Sharpe Ratio of 1.49. The chart below compares the historical Sharpe Ratios of MGTIX and AGTHX, 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

MGTIX vs. AGTHX - Drawdown Comparison

The maximum MGTIX drawdown since its inception was -60.05%, which is greater than AGTHX's maximum drawdown of -51.91%. Use the drawdown chart below to compare losses from any high point for MGTIX and AGTHX.

Drawdown Indicators

	MGTIX	AGTHX	Difference
Max Drawdown Largest peak-to-trough decline	-60.05%	-51.91%	-8.14%
Max Drawdown (1Y) Largest decline over 1 year	-13.71%	-13.76%	+0.05%
Max Drawdown (3Y) Largest decline over 3 years	-18.65%	-21.57%	+2.92%
Max Drawdown (5Y) Largest decline over 5 years	-26.52%	-36.38%	+9.86%
Max Drawdown (10Y) Largest decline over 10 years	-32.42%	-36.38%	+3.96%
Current Drawdown Current decline from peak	-4.93%	-1.05%	-3.88%
Average Drawdown Average peak-to-trough decline	-17.11%	-9.19%	-7.92%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.21%	3.59%	+0.62%

Volatility

MGTIX vs. AGTHX - Volatility Comparison

The current volatility for MFS Massachusetts Investors Growth Stock Fund (MGTIX) is 4.87%, while American Funds The Growth Fund of America Class A (AGTHX) has a volatility of 6.90%. This indicates that MGTIX experiences smaller price fluctuations and is considered to be less risky than AGTHX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MGTIX	AGTHX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.87%	6.90%	-2.03%
Volatility (6M) Calculated over the trailing 6-month period	10.62%	13.13%	-2.51%
Volatility (1Y) Calculated over the trailing 1-year period	13.10%	16.27%	-3.17%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.59%	20.43%	-2.84%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.24%	19.78%	-1.54%

MGTIX vs. AGTHX - Expense Ratio Comparison

MGTIX has a 0.45% expense ratio, which is lower than AGTHX's 0.59% expense ratio.

Dividends

MGTIX vs. AGTHX - Dividend Comparison

MGTIX's dividend yield for the trailing twelve months is around 11.41%, more than AGTHX's 9.78% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
AGTHX American Funds The Growth Fund of America Class A	9.78%	10.69%	8.99%	7.40%	4.05%	8.18%	4.30%	7.15%	11.99%	7.03%	6.61%	8.87%
MGTIX MFS Massachusetts Investors Growth Stock Fund	11.41%	11.08%	16.84%	4.17%	4.59%	10.30%	7.43%	7.38%	10.72%	6.83%	5.00%	6.61%

Frequently Asked Questions

Can I hold both MGTIX and AGTHX in my portfolio?

MGTIX and AGTHX have a correlation of 0.84, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MGTIX or AGTHX?

AGTHX has higher volatility (6.90%) compared to MGTIX (4.87%). In terms of maximum drawdown, MGTIX dropped -60.05% vs AGTHX's -51.91%.

Which has better risk-adjusted returns?

AGTHX currently has the higher Sharpe Ratio (1.49 vs 0.56), 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.