BMSLX vs. TARKX

Last updated Jun 25, 2026

BMSLX (MFS Blended Research Mid Cap Equity Fund) and TARKX (Tarkio Fund) are both Mid Cap Blend Equities funds. Over the past 5 years, BMSLX returned 10.82%/yr vs 10.77%/yr for TARKX. Their correlation of 0.84 suggests significant overlap in exposure. BMSLX charges 0.59%/yr vs 1.00%/yr for TARKX.

Performance

BMSLX vs. TARKX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Blended Research Mid Cap Equity Fund (BMSLX) and Tarkio Fund (TARKX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BMSLX achieves a 15.46% return, which is significantly lower than TARKX's 19.99% return.

BMSLX

• 1D: -0.87%
• 1M: 4.72%
• YTD: 15.46%
• 6M: 13.77%
• 1Y: 21.27%
• 3Y*: 19.06%
• 5Y*: 10.82%
• 10Y*: —

TARKX

• 1D: -2.63%
• 1M: 0.60%
• YTD: 19.99%
• 6M: 17.71%
• 1Y: 52.70%
• 3Y*: 27.45%
• 5Y*: 10.77%
• 10Y*: 15.43%

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

BMSLX vs. TARKX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BMSLX MFS Blended Research Mid Cap Equity Fund	15.46%	8.08%	19.25%	19.81%	-13.70%	26.54%	10.44%	30.21%	-11.11%	18.04%
TARKX Tarkio Fund	19.99%	30.18%	21.72%	26.33%	-30.39%	24.41%	27.00%	29.54%	-23.30%	29.04%

Correlation

The correlation between BMSLX and TARKX is 0.69, 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	0.69
Correlation (3Y) Calculated over the trailing 3-year period	0.78
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (All Time) Calculated using the full available price history since Aug 23, 2016	0.84

The correlation between BMSLX and TARKX shifts across timeframes, from 0.69 (1 year) to 0.85 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

BMSLX vs. TARKX — Risk / Return Rank

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

BMSLX

BMSLX Risk / Return Rank: 39
BMSLX Sharpe Ratio Rank: 35
BMSLX Sortino Ratio Rank: 38
BMSLX Omega Ratio Rank: 33
BMSLX Calmar Ratio Rank: 47
BMSLX Martin Ratio Rank: 42

TARKX

TARKX Risk / Return Rank: 60
TARKX Sharpe Ratio Rank: 57
TARKX Sortino Ratio Rank: 50
TARKX Omega Ratio Rank: 45
TARKX Calmar Ratio Rank: 78
TARKX Martin Ratio Rank: 68

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.

BMSLX vs. TARKX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Blended Research Mid Cap Equity Fund (BMSLX) and Tarkio Fund (TARKX). 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.

	BMSLX	TARKX	Difference
Sharpe ratio: Return per unit of total volatility	1.53	1.97	-0.44
Sortino ratio: Return per unit of downside risk	2.28	2.61	-0.33
Omega ratio: Gain probability vs. loss probability	1.27	1.33	-0.05
Calmar ratio: Return relative to maximum drawdown	2.44	3.28	-0.84
Martin ratio: Return relative to average drawdown	8.33	11.96	-3.63

BMSLX vs. TARKX - Sharpe Ratio Comparison

The current BMSLX Sharpe Ratio is 1.53, which is comparable to the TARKX Sharpe Ratio of 1.97. The chart below compares the historical Sharpe Ratios of BMSLX and TARKX, 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

BMSLX vs. TARKX - Drawdown Comparison

The maximum BMSLX drawdown since its inception was -41.06%, roughly equal to the maximum TARKX drawdown of -40.55%. Use the drawdown chart below to compare losses from any high point for BMSLX and TARKX.

Drawdown Indicators

	BMSLX	TARKX	Difference
Max Drawdown Largest peak-to-trough decline	-41.06%	-40.55%	-0.51%
Max Drawdown (1Y) Largest decline over 1 year	-9.17%	-16.99%	+7.82%
Max Drawdown (3Y) Largest decline over 3 years	-22.28%	-36.99%	+14.71%
Max Drawdown (5Y) Largest decline over 5 years	-22.28%	-40.38%	+18.10%
Max Drawdown (10Y) Largest decline over 10 years	—	-40.55%	—
Current Drawdown Current decline from peak	-0.87%	-3.81%	+2.94%
Average Drawdown Average peak-to-trough decline	-5.02%	-10.34%	+5.32%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.68%	4.66%	-1.98%

Volatility

BMSLX vs. TARKX - Volatility Comparison

The current volatility for MFS Blended Research Mid Cap Equity Fund (BMSLX) is 4.45%, while Tarkio Fund (TARKX) has a volatility of 9.29%. This indicates that BMSLX experiences smaller price fluctuations and is considered to be less risky than TARKX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BMSLX	TARKX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.45%	9.29%	-4.84%
Volatility (6M) Calculated over the trailing 6-month period	11.15%	21.74%	-10.59%
Volatility (1Y) Calculated over the trailing 1-year period	14.61%	28.34%	-13.73%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.49%	27.72%	-9.23%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.71%	26.73%	-7.02%

BMSLX vs. TARKX - Expense Ratio Comparison

BMSLX has a 0.59% expense ratio, which is lower than TARKX's 1.00% expense ratio.

Dividends

BMSLX vs. TARKX - Dividend Comparison

BMSLX's dividend yield for the trailing twelve months is around 2.67%, less than TARKX's 4.59% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BMSLX MFS Blended Research Mid Cap Equity Fund	2.67%	3.08%	10.98%	2.32%	5.15%	23.06%	0.94%	4.90%	8.27%	2.63%	0.47%	0.00%
TARKX Tarkio Fund	4.59%	5.50%	1.51%	2.98%	10.62%	1.40%	0.50%	5.21%	3.34%	1.70%	0.47%	0.36%

Frequently Asked Questions

Can I hold both BMSLX and TARKX in my portfolio?

BMSLX and TARKX have a correlation of 0.69, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BMSLX or TARKX?

TARKX has higher volatility (9.29%) compared to BMSLX (4.45%). In terms of maximum drawdown, BMSLX dropped -41.06% vs TARKX's -40.55%.

Which has better risk-adjusted returns?

TARKX currently has the higher Sharpe Ratio (1.97 vs 1.53), 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.