OSTFX vs. FSKAX

Last updated Apr 1, 2026

Compare and contrast key facts about Osterweis Fund (OSTFX) and Fidelity Total Market Index Fund (FSKAX).

OSTFX is managed by Osterweis. It was launched on Oct 1, 1993. FSKAX is managed by Fidelity.

Performance

OSTFX vs. FSKAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Osterweis Fund (OSTFX) and Fidelity Total Market Index Fund (FSKAX). The values are adjusted to include any dividend payments, if applicable.

OSTFX vs. FSKAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OSTFX Osterweis Fund	-6.94%	12.85%	13.48%	22.64%	-22.01%	22.58%	23.20%	43.39%	-7.85%	14.82%
FSKAX Fidelity Total Market Index Fund	-6.77%	17.06%	23.89%	26.12%	-19.53%	25.66%	20.79%	30.92%	-5.32%	20.85%

Returns By Period

The year-to-date returns for both investments are quite close, with OSTFX having a -6.94% return and FSKAX slightly higher at -6.77%. Over the past 10 years, OSTFX has underperformed FSKAX with an annualized return of 10.76%, while FSKAX has yielded a comparatively higher 13.23% annualized return.

OSTFX

• 1D: -0.27%
• 1M: -9.09%
• YTD: -6.94%
• 6M: -3.70%
• 1Y: 8.57%
• 3Y*: 11.19%
• 5Y*: 5.98%
• 10Y*: 10.76%

FSKAX

• 1D: -0.47%
• 1M: -7.69%
• YTD: -6.77%
• 6M: -4.56%
• 1Y: 14.73%
• 3Y*: 16.72%
• 5Y*: 10.13%
• 10Y*: 13.23%

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

OSTFX vs. FSKAX - Expense Ratio Comparison

OSTFX has a 0.95% expense ratio, which is higher than FSKAX's 0.02% expense ratio.

OSTFX

Osterweis Fund

FSKAX

Fidelity Total Market Index Fund

Return for Risk

OSTFX vs. FSKAX — Risk / Return Rank

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

OSTFX

OSTFX Risk / Return Rank: 23
OSTFX Sharpe Ratio Rank: 22
OSTFX Sortino Ratio Rank: 23
OSTFX Omega Ratio Rank: 21
OSTFX Calmar Ratio Rank: 23
OSTFX Martin Ratio Rank: 25

FSKAX

FSKAX Risk / Return Rank: 45
FSKAX Sharpe Ratio Rank: 40
FSKAX Sortino Ratio Rank: 44
FSKAX Omega Ratio Rank: 48
FSKAX Calmar Ratio Rank: 41
FSKAX Martin Ratio Rank: 52

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.

OSTFX vs. FSKAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Osterweis Fund (OSTFX) and Fidelity Total Market Index Fund (FSKAX). 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.

	OSTFX	FSKAX	Difference
Sharpe ratio Return per unit of total volatility	0.59	0.83	-0.24
Sortino ratio Return per unit of downside risk	0.96	1.29	-0.33
Omega ratio Gain probability vs. loss probability	1.13	1.19	-0.06
Calmar ratio Return relative to maximum drawdown	0.69	1.04	-0.35
Martin ratio Return relative to average drawdown	2.79	5.05	-2.25
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

OSTFX vs. FSKAX - Sharpe Ratio Comparison

The current OSTFX Sharpe Ratio is 0.59, which is comparable to the FSKAX Sharpe Ratio of 0.83. The chart below compares the historical Sharpe Ratios of OSTFX and FSKAX, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	OSTFX	FSKAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.59	0.83	-0.24
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.39	0.59	-0.20
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.64	0.72	-0.08
Sharpe Ratio (All Time) Calculated using the full available price history	0.69	0.78	-0.09

Correlation

The correlation between OSTFX and FSKAX is 0.94, which is considered to be high. That indicates a strong positive relationship between their price movements. Having highly-correlated positions in a portfolio may signal a lack of diversification, potentially leading to increased risk during market downturns.

Dividends

OSTFX vs. FSKAX - Dividend Comparison

OSTFX's dividend yield for the trailing twelve months is around 6.43%, more than FSKAX's 1.09% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OSTFX Osterweis Fund	6.43%	5.98%	14.93%	4.01%	7.81%	12.83%	5.48%	14.46%	29.80%	43.97%	7.35%	22.55%
FSKAX Fidelity Total Market Index Fund	1.09%	1.01%	1.19%	1.41%	1.62%	1.15%	1.45%	1.94%	2.54%	2.07%	2.43%	0.82%

Drawdowns

OSTFX vs. FSKAX - Drawdown Comparison

The maximum OSTFX drawdown since its inception was -40.63%, which is greater than FSKAX's maximum drawdown of -35.01%. Use the drawdown chart below to compare losses from any high point for OSTFX and FSKAX.

Drawdown Indicators

	OSTFX	FSKAX	Difference
Max Drawdown Largest peak-to-trough decline	-40.63%	-35.01%	-5.62%
Max Drawdown (1Y) Largest decline over 1 year	-10.06%	-12.42%	+2.36%
Max Drawdown (5Y) Largest decline over 5 years	-27.62%	-25.39%	-2.23%
Max Drawdown (10Y) Largest decline over 10 years	-32.54%	-35.01%	+2.47%
Current Drawdown Current decline from peak	-10.06%	-8.92%	-1.14%
Average Drawdown Average peak-to-trough decline	-6.87%	-4.05%	-2.82%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.49%	2.57%	-0.08%

Volatility

OSTFX vs. FSKAX - Volatility Comparison

The current volatility for Osterweis Fund (OSTFX) is 3.92%, while Fidelity Total Market Index Fund (FSKAX) has a volatility of 4.42%. This indicates that OSTFX experiences smaller price fluctuations and is considered to be less risky than FSKAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OSTFX	FSKAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.92%	4.42%	-0.50%
Volatility (6M) Calculated over the trailing 6-month period	8.47%	9.40%	-0.93%
Volatility (1Y) Calculated over the trailing 1-year period	15.37%	18.50%	-3.13%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.60%	17.38%	-1.78%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.76%	18.42%	-1.66%