FUNFX vs. MEGBX

Last updated Jun 24, 2026

FUNFX (American Funds Fundamental Investors® Class F-3) and MEGBX (MFS Growth Fund) are both mutual funds - FUNFX is a Large Cap Blend Equities fund managed by American Funds, while MEGBX is a Large Cap Growth Equities fund managed by MFS. Over the past 5 years, FUNFX returned 14.98%/yr vs 13.39%/yr for MEGBX. Their correlation of 0.89 suggests significant overlap in exposure. FUNFX charges 0.28%/yr vs 1.59%/yr for MEGBX.

Performance

FUNFX vs. MEGBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Funds Fundamental Investors® Class F-3 (FUNFX) and MFS Growth Fund (MEGBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FUNFX achieves a 14.40% return, which is significantly higher than MEGBX's 3.21% return.

FUNFX

• 1D: -0.54%
• 1M: 1.92%
• YTD: 14.40%
• 6M: 14.09%
• 1Y: 31.89%
• 3Y*: 25.64%
• 5Y*: 14.98%
• 10Y*: —

MEGBX

• 1D: -1.47%
• 1M: -0.22%
• YTD: 3.21%
• 6M: 2.11%
• 1Y: 12.23%
• 3Y*: 27.28%
• 5Y*: 13.39%
• 10Y*: 17.62%

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

FUNFX vs. MEGBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FUNFX American Funds Fundamental Investors® Class F-3	14.40%	24.57%	23.13%	26.25%	-16.38%	22.81%	15.28%	27.47%	-7.87%	19.59%
MEGBX MFS Growth Fund	3.21%	11.25%	61.25%	34.81%	-31.83%	22.34%	30.36%	36.33%	1.21%	24.52%

Correlation

The correlation between FUNFX and MEGBX is 0.88, 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	0.88
Correlation (3Y) Calculated over the trailing 3-year period	0.88
Correlation (5Y) Calculated over the trailing 5-year period	0.90
Correlation (All Time) Calculated using the full available price history since Feb 1, 2017	0.89

The correlation between FUNFX and MEGBX has been stable across timeframes, ranging from 0.88 to 0.90 - a consistent structural relationship.

Return for Risk

FUNFX vs. MEGBX — Risk / Return Rank

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

FUNFX

FUNFX Risk / Return Rank: 70
FUNFX Sharpe Ratio Rank: 71
FUNFX Sortino Ratio Rank: 63
FUNFX Omega Ratio Rank: 63
FUNFX Calmar Ratio Rank: 71
FUNFX Martin Ratio Rank: 81

MEGBX

MEGBX Risk / Return Rank: 10
MEGBX Sharpe Ratio Rank: 11
MEGBX Sortino Ratio Rank: 10
MEGBX Omega Ratio Rank: 10
MEGBX Calmar Ratio Rank: 8
MEGBX Martin Ratio Rank: 9

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.

FUNFX vs. MEGBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Funds Fundamental Investors® Class F-3 (FUNFX) and MFS Growth Fund (MEGBX). 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.

	FUNFX	MEGBX	Difference
Sharpe ratio: Return per unit of total volatility	2.25	0.80	+1.45
Sortino ratio: Return per unit of downside risk	3.03	1.18	+1.85
Omega ratio: Gain probability vs. loss probability	1.40	1.15	+0.26
Calmar ratio: Return relative to maximum drawdown	3.10	0.76	+2.34
Martin ratio: Return relative to average drawdown	13.98	2.42	+11.56

FUNFX vs. MEGBX - Sharpe Ratio Comparison

The current FUNFX Sharpe Ratio is 2.25, which is higher than the MEGBX Sharpe Ratio of 0.80. The chart below compares the historical Sharpe Ratios of FUNFX and MEGBX, 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

FUNFX vs. MEGBX - Drawdown Comparison

The maximum FUNFX drawdown since its inception was -33.92%, smaller than the maximum MEGBX drawdown of -72.95%. Use the drawdown chart below to compare losses from any high point for FUNFX and MEGBX.

Drawdown Indicators

	FUNFX	MEGBX	Difference
Max Drawdown Largest peak-to-trough decline	-33.92%	-72.95%	+39.03%
Max Drawdown (1Y) Largest decline over 1 year	-10.62%	-17.64%	+7.02%
Max Drawdown (3Y) Largest decline over 3 years	-17.93%	-23.39%	+5.46%
Max Drawdown (5Y) Largest decline over 5 years	-24.88%	-36.73%	+11.85%
Max Drawdown (10Y) Largest decline over 10 years	—	-36.73%	—
Current Drawdown Current decline from peak	-0.76%	-2.82%	+2.06%
Average Drawdown Average peak-to-trough decline	-4.69%	-21.73%	+17.04%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.35%	5.54%	-3.19%

Volatility

FUNFX vs. MEGBX - Volatility Comparison

The current volatility for American Funds Fundamental Investors® Class F-3 (FUNFX) is 5.60%, while MFS Growth Fund (MEGBX) has a volatility of 6.54%. This indicates that FUNFX experiences smaller price fluctuations and is considered to be less risky than MEGBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FUNFX	MEGBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.60%	6.54%	-0.94%
Volatility (6M) Calculated over the trailing 6-month period	11.72%	13.39%	-1.67%
Volatility (1Y) Calculated over the trailing 1-year period	14.65%	16.83%	-2.18%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.94%	23.62%	-6.68%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.14%	22.12%	-3.98%

FUNFX vs. MEGBX - Expense Ratio Comparison

FUNFX has a 0.28% expense ratio, which is lower than MEGBX's 1.59% expense ratio.

Dividends

FUNFX vs. MEGBX - Dividend Comparison

FUNFX's dividend yield for the trailing twelve months is around 7.57%, less than MEGBX's 25.77% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FUNFX American Funds Fundamental Investors® Class F-3	7.57%	8.83%	9.21%	6.10%	5.33%	11.29%	2.90%	7.21%	9.65%	7.57%	0.00%	0.00%
MEGBX MFS Growth Fund	25.77%	26.60%	40.46%	7.21%	1.51%	3.91%	4.94%	2.13%	4.95%	3.26%	2.03%	4.61%

Frequently Asked Questions

Can I hold both FUNFX and MEGBX in my portfolio?

FUNFX and MEGBX have a correlation of 0.88, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FUNFX or MEGBX?

MEGBX has higher volatility (6.54%) compared to FUNFX (5.60%). In terms of maximum drawdown, FUNFX dropped -33.92% vs MEGBX's -72.95%.

Which has better risk-adjusted returns?

FUNFX currently has the higher Sharpe Ratio (2.25 vs 0.80), 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.