TARKX vs. BMSLX

Last updated Jun 4, 2026

TARKX (Tarkio Fund) and BMSLX (MFS Blended Research Mid Cap Equity Fund) are both Mid Cap Blend Equities funds. Over the past 5 years, TARKX returned 11.17%/yr vs 10.72%/yr for BMSLX. Their correlation of 0.84 suggests significant overlap in exposure. TARKX charges 1.00%/yr vs 0.59%/yr for BMSLX.

Performance

TARKX vs. BMSLX - Performance Comparison

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

Returns By Period

In the year-to-date period, TARKX achieves a 24.74% return, which is significantly higher than BMSLX's 13.91% return.

TARKX

• 1D: 2.17%
• 1M: 7.27%
• YTD: 24.74%
• 6M: 22.99%
• 1Y: 62.96%
• 3Y*: 29.68%
• 5Y*: 11.17%
• 10Y*: 15.29%

BMSLX

• 1D: 0.78%
• 1M: 5.44%
• YTD: 13.91%
• 6M: 13.69%
• 1Y: 21.65%
• 3Y*: 18.96%
• 5Y*: 10.72%
• 10Y*: —

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

TARKX vs. BMSLX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TARKX Tarkio Fund	24.74%	30.18%	21.72%	26.33%	-30.39%	24.41%	27.00%	29.54%	-23.30%	29.04%
BMSLX MFS Blended Research Mid Cap Equity Fund	13.91%	8.08%	19.25%	19.81%	-13.70%	26.54%	10.44%	30.21%	-11.11%	18.04%

Correlation

The correlation between TARKX and BMSLX is 0.68, 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	0.68
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 24, 2016	0.84

The correlation between TARKX and BMSLX shifts across timeframes, from 0.68 (1 year) to 0.85 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

TARKX vs. BMSLX — Risk / Return Rank

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

TARKX

TARKX Risk / Return Rank: 68
TARKX Sharpe Ratio Rank: 71
TARKX Sortino Ratio Rank: 55
TARKX Omega Ratio Rank: 53
TARKX Calmar Ratio Rank: 84
TARKX Martin Ratio Rank: 79

BMSLX

BMSLX Risk / Return Rank: 36
BMSLX Sharpe Ratio Rank: 32
BMSLX Sortino Ratio Rank: 33
BMSLX Omega Ratio Rank: 31
BMSLX Calmar Ratio Rank: 44
BMSLX Martin Ratio Rank: 40

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.

TARKX vs. BMSLX - Risk-Adjusted Trends Comparison

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

	TARKX	BMSLX	Difference
Sharpe ratio: Return per unit of total volatility	2.46	1.60	+0.85
Sortino ratio: Return per unit of downside risk	3.14	2.37	+0.77
Omega ratio: Gain probability vs. loss probability	1.40	1.29	+0.11
Calmar ratio: Return relative to maximum drawdown	3.98	2.50	+1.47
Martin ratio: Return relative to average drawdown	14.81	8.56	+6.25
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TARKX vs. BMSLX - Sharpe Ratio Comparison

The current TARKX Sharpe Ratio is 2.46, which is higher than the BMSLX Sharpe Ratio of 1.60. The chart below compares the historical Sharpe Ratios of TARKX and BMSLX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	TARKX	BMSLX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.46	1.60	+0.85
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.41	0.58	-0.18
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.57	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.56	0.60	-0.05

Drawdowns

TARKX vs. BMSLX - Drawdown Comparison

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

Drawdown Indicators

	TARKX	BMSLX	Difference
Max Drawdown Largest peak-to-trough decline	-40.55%	-41.06%	+0.51%
Max Drawdown (1Y) Largest decline over 1 year	-16.99%	-9.17%	-7.82%
Max Drawdown (3Y) Largest decline over 3 years	-36.99%	-22.28%	-14.71%
Max Drawdown (5Y) Largest decline over 5 years	-40.38%	-22.28%	-18.10%
Max Drawdown (10Y) Largest decline over 10 years	-40.55%	—	—
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-10.37%	-5.05%	-5.32%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.55%	2.68%	+1.87%

Volatility

TARKX vs. BMSLX - Volatility Comparison

Tarkio Fund (TARKX) has a higher volatility of 8.62% compared to MFS Blended Research Mid Cap Equity Fund (BMSLX) at 3.75%. This indicates that TARKX's price experiences larger fluctuations and is considered to be riskier than BMSLX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TARKX	BMSLX	Difference
Volatility (1M) Calculated over the trailing 1-month period	8.62%	3.75%	+4.87%
Volatility (6M) Calculated over the trailing 6-month period	21.04%	10.74%	+10.30%
Volatility (1Y) Calculated over the trailing 1-year period	27.50%	14.31%	+13.19%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	27.54%	18.43%	+9.11%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	26.68%	19.73%	+6.95%

TARKX vs. BMSLX - Expense Ratio Comparison

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

Dividends

TARKX vs. BMSLX - Dividend Comparison

TARKX's dividend yield for the trailing twelve months is around 4.41%, more than BMSLX's 2.71% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BMSLX MFS Blended Research Mid Cap Equity Fund	2.71%	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	4.41%	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 TARKX and BMSLX in my portfolio?

TARKX and BMSLX have a correlation of 0.68, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TARKX or BMSLX?

TARKX has higher volatility (8.62%) compared to BMSLX (3.75%). In terms of maximum drawdown, TARKX dropped -40.55% vs BMSLX's -41.06%.

Which has better risk-adjusted returns?

TARKX currently has the higher Sharpe Ratio (2.46 vs 1.60), 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.