OTCKX vs. EEOFX

Last updated Aug 4, 2026

OTCKX (MFS Mid Cap Growth Fund Class R6) and EEOFX (Essex Environmental Opportunities Fund) are both Mid Cap Growth Equities funds. Over the past 5 years, OTCKX returned 4.01%/yr vs -1.25%/yr for EEOFX. Their 0.77 correlation means they have sometimes moved together and sometimes differently. OTCKX charges 0.65%/yr vs 2.11%/yr for EEOFX.

Performance

OTCKX vs. EEOFX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Mid Cap Growth Fund Class R6 (OTCKX) and Essex Environmental Opportunities Fund (EEOFX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, OTCKX achieves a 2.29% return, which is significantly lower than EEOFX's 9.66% return.

OTCKX

• 1D: -0.10%
• 1M: -3.32%
• 6M: 2.54%
• YTD: 2.29%
• 1Y: -0.97%
• 3Y*: 12.44%
• 5Y*: 4.01%
• 10Y*: 12.29%
• ALL TIME*: 11.38%

EEOFX

• 1D: 0.06%
• 1M: -8.95%
• 6M: 4.79%
• YTD: 9.66%
• 1Y: 18.22%
• 3Y*: 6.38%
• 5Y*: -1.25%
• 10Y*: —
• ALL TIME*: 7.58%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
EEOFX Essex Environmental Opportunities Fund	$0.00	$0.00	$0.00
OTCKX MFS Mid Cap Growth Fund Class R6	$0.00	$0.00	$0.00

OTCKX vs. EEOFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OTCKX MFS Mid Cap Growth Fund Class R6	2.29%	3.75%	26.48%	21.50%	-28.29%	14.09%	35.81%	37.93%	1.19%	6.65%
EEOFX Essex Environmental Opportunities Fund	9.66%	23.55%	1.32%	-1.53%	-27.88%	10.83%	62.80%	25.43%	-15.79%	3.20%

Correlation

The correlation between OTCKX and EEOFX is 0.74, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.74
Correlation (3Y) Balances recent behavior with more history.	0.73
Correlation (5Y) Shows whether the relationship held over a longer period.	0.78
Correlation (All Time) Calculated using the full available price history since Sep 1, 2017	0.77

The correlation between OTCKX and EEOFX has been stable across timeframes, ranging from 0.73 to 0.78 - a consistent structural relationship.

Return for Risk

OTCKX vs. EEOFX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

OTCKX

OTCKX Risk / Return Rank: 3
OTCKX Sharpe Ratio Rank: 3
OTCKX Sortino Ratio Rank: 3
OTCKX Omega Ratio Rank: 3
OTCKX Calmar Ratio Rank: 3
OTCKX Martin Ratio Rank: 3

EEOFX

EEOFX Risk / Return Rank: 17
EEOFX Sharpe Ratio Rank: 16
EEOFX Sortino Ratio Rank: 17
EEOFX Omega Ratio Rank: 16
EEOFX Calmar Ratio Rank: 16
EEOFX Martin Ratio Rank: 18

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

OTCKX vs. EEOFX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Mid Cap Growth Fund Class R6 (OTCKX) and Essex Environmental Opportunities Fund (EEOFX). 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.

	OTCKX	EEOFX	Difference
Sharpe ratio: Return per unit of total volatility	-0.12	0.67	-0.78
Sortino ratio: Return per unit of downside risk	-0.04	1.08	-1.12
Omega ratio: Gain probability vs. loss probability	1.00	1.13	-0.13
Calmar ratio: Return relative to maximum drawdown	-0.13	0.88	-1.00
Martin ratio: Return relative to average drawdown	-0.32	2.78	-3.10

OTCKX vs. EEOFX - Sharpe Ratio Comparison

The current OTCKX Sharpe Ratio is -0.12, which is lower than the EEOFX Sharpe Ratio of 0.67. The chart below compares the historical Sharpe Ratios of OTCKX and EEOFX, 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

OTCKX vs. EEOFX - Drawdown Comparison

The maximum OTCKX drawdown since its inception was -36.64%, smaller than the maximum EEOFX drawdown of -50.17%. Use the drawdown chart below to compare losses from any high point for OTCKX and EEOFX.

Drawdown Indicators

	OTCKX	EEOFX	Difference
Max Drawdown Largest peak-to-trough decline	-36.64%	-50.17%	+13.53%
Max Drawdown (1Y) Largest decline over 1 year	-16.31%	-19.43%	+3.12%
Max Drawdown (3Y) Largest decline over 3 years	-20.99%	-27.36%	+6.37%
Max Drawdown (5Y) Largest decline over 5 years	-36.64%	-50.17%	+13.53%
Max Drawdown (10Y) Largest decline over 10 years	-36.64%	—	—
Current Drawdown Current decline from peak	-5.37%	-16.70%	+11.33%
Average Drawdown Average peak-to-trough decline	-7.31%	-19.48%	+12.17%
Ulcer Index Depth and duration of drawdowns from previous peaks	6.48%	6.08%	+0.40%

Volatility

OTCKX vs. EEOFX - Volatility Comparison

The current volatility for MFS Mid Cap Growth Fund Class R6 (OTCKX) is 4.76%, while Essex Environmental Opportunities Fund (EEOFX) has a volatility of 8.17%. This indicates that OTCKX experiences smaller price fluctuations and is considered to be less risky than EEOFX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OTCKX	EEOFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.76%	8.17%	-3.41%
Volatility (6M) Calculated over the trailing 6-month period	14.54%	20.52%	-5.98%
Volatility (1Y) Calculated over the trailing 1-year period	17.70%	25.48%	-7.78%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.57%	25.48%	-4.91%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.12%	24.97%	-4.85%

OTCKX vs. EEOFX - Expense Ratio Comparison

OTCKX has a 0.65% expense ratio, which is lower than EEOFX's 2.11% expense ratio.

Dividends

OTCKX vs. EEOFX - Dividend Comparison

OTCKX's dividend yield for the trailing twelve months is around 14.55%, more than EEOFX's 0.06% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
EEOFX Essex Environmental Opportunities Fund	0.06%	0.06%	0.00%	0.00%	0.01%	6.63%	1.62%	0.00%	0.00%	0.00%	0.00%	0.00%
OTCKX MFS Mid Cap Growth Fund Class R6	14.55%	14.88%	16.85%	0.00%	0.00%	3.35%	0.77%	0.81%	4.40%	8.28%	5.38%	2.72%

Frequently Asked Questions

Can I hold both OTCKX and EEOFX in my portfolio?

OTCKX and EEOFX 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, OTCKX or EEOFX?

EEOFX has higher volatility (8.17%) compared to OTCKX (4.76%). In terms of maximum drawdown, OTCKX dropped -36.64% vs EEOFX's -50.17%.

Which has better risk-adjusted returns?

EEOFX currently has the higher Sharpe Ratio (0.67 vs -0.12), 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.