FSTSX vs. OBIOX

Last updated Jun 23, 2026

FSTSX (Fidelity Series International Small Cap Fund) and OBIOX (Oberweis International Opportunities Fund) are both Foreign Small & Mid Cap Equities funds. Over the past 10 years, FSTSX returned 9.97%/yr vs 7.23%/yr for OBIOX. Their correlation of 0.85 suggests significant overlap in exposure. FSTSX charges 0.03%/yr vs 1.60%/yr for OBIOX.

Performance

FSTSX vs. OBIOX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Series International Small Cap Fund (FSTSX) and Oberweis International Opportunities Fund (OBIOX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSTSX achieves a 6.76% return, which is significantly lower than OBIOX's 9.91% return. Over the past 10 years, FSTSX has outperformed OBIOX with an annualized return of 9.97%, while OBIOX has yielded a comparatively lower 7.23% annualized return.

FSTSX

• 1D: 0.37%
• 1M: -1.29%
• YTD: 6.76%
• 6M: 7.42%
• 1Y: 16.55%
• 3Y*: 14.80%
• 5Y*: 6.53%
• 10Y*: 9.97%

OBIOX

• 1D: 0.57%
• 1M: -0.04%
• YTD: 9.91%
• 6M: 10.05%
• 1Y: 19.24%
• 3Y*: 15.53%
• 5Y*: -0.11%
• 10Y*: 7.23%

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

FSTSX vs. OBIOX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FSTSX Fidelity Series International Small Cap Fund	6.76%	27.49%	4.97%	18.36%	-26.25%	18.29%	19.61%	28.24%	-13.19%	34.44%
OBIOX Oberweis International Opportunities Fund	9.91%	30.71%	7.54%	4.90%	-37.06%	1.41%	62.87%	22.87%	-26.57%	40.90%

Correlation

The correlation between FSTSX and OBIOX is 0.83, 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	0.83
Correlation (3Y) Calculated over the trailing 3-year period	0.86
Correlation (5Y) Calculated over the trailing 5-year period	0.89
Correlation (10Y) Calculated over the trailing 10-year period	0.84
Correlation (All Time) Calculated using the full available price history since Dec 4, 2009	0.85

The correlation between FSTSX and OBIOX has been stable across timeframes, ranging from 0.83 to 0.89 - a consistent structural relationship.

Return for Risk

FSTSX vs. OBIOX — Risk / Return Rank

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

FSTSX

FSTSX Risk / Return Rank: 18
FSTSX Sharpe Ratio Rank: 18
FSTSX Sortino Ratio Rank: 18
FSTSX Omega Ratio Rank: 18
FSTSX Calmar Ratio Rank: 18
FSTSX Martin Ratio Rank: 20

OBIOX

OBIOX Risk / Return Rank: 16
OBIOX Sharpe Ratio Rank: 17
OBIOX Sortino Ratio Rank: 17
OBIOX Omega Ratio Rank: 17
OBIOX Calmar Ratio Rank: 14
OBIOX Martin Ratio Rank: 16

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.

FSTSX vs. OBIOX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Series International Small Cap Fund (FSTSX) and Oberweis International Opportunities Fund (OBIOX). 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.

	FSTSX	OBIOX	Difference
Sharpe ratio: Return per unit of total volatility	1.13	1.07	+0.05
Sortino ratio: Return per unit of downside risk	1.68	1.58	+0.09
Omega ratio: Gain probability vs. loss probability	1.21	1.20	0.00
Calmar ratio: Return relative to maximum drawdown	1.42	1.19	+0.23
Martin ratio: Return relative to average drawdown	4.75	4.11	+0.63

FSTSX vs. OBIOX - Sharpe Ratio Comparison

The current FSTSX Sharpe Ratio is 1.13, which is comparable to the OBIOX Sharpe Ratio of 1.07. The chart below compares the historical Sharpe Ratios of FSTSX and OBIOX, 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

FSTSX vs. OBIOX - Drawdown Comparison

The maximum FSTSX drawdown since its inception was -38.91%, smaller than the maximum OBIOX drawdown of -71.17%. Use the drawdown chart below to compare losses from any high point for FSTSX and OBIOX.

Drawdown Indicators

	FSTSX	OBIOX	Difference
Max Drawdown Largest peak-to-trough decline	-38.91%	-71.17%	+32.26%
Max Drawdown (1Y) Largest decline over 1 year	-11.22%	-15.64%	+4.42%
Max Drawdown (3Y) Largest decline over 3 years	-14.47%	-17.48%	+3.01%
Max Drawdown (5Y) Largest decline over 5 years	-38.91%	-51.47%	+12.56%
Max Drawdown (10Y) Largest decline over 10 years	-38.91%	-51.47%	+12.56%
Current Drawdown Current decline from peak	-1.95%	-10.40%	+8.45%
Average Drawdown Average peak-to-trough decline	-7.88%	-21.42%	+13.54%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.35%	4.51%	-1.16%

Volatility

FSTSX vs. OBIOX - Volatility Comparison

The current volatility for Fidelity Series International Small Cap Fund (FSTSX) is 4.68%, while Oberweis International Opportunities Fund (OBIOX) has a volatility of 6.50%. This indicates that FSTSX experiences smaller price fluctuations and is considered to be less risky than OBIOX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSTSX	OBIOX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.68%	6.50%	-1.82%
Volatility (6M) Calculated over the trailing 6-month period	11.60%	15.02%	-3.42%
Volatility (1Y) Calculated over the trailing 1-year period	14.16%	17.28%	-3.12%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.49%	19.89%	-3.40%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	15.94%	19.85%	-3.91%

FSTSX vs. OBIOX - Expense Ratio Comparison

FSTSX has a 0.03% expense ratio, which is lower than OBIOX's 1.60% expense ratio.

Dividends

FSTSX vs. OBIOX - Dividend Comparison

FSTSX's dividend yield for the trailing twelve months is around 14.27%, more than OBIOX's 1.00% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSTSX Fidelity Series International Small Cap Fund	14.27%	15.24%	10.22%	3.34%	6.38%	13.22%	0.81%	4.27%	10.99%	6.30%	4.01%	7.32%
OBIOX Oberweis International Opportunities Fund	1.00%	1.10%	1.27%	0.43%	0.00%	20.69%	0.40%	1.23%	17.03%	11.47%	0.07%	0.19%

Frequently Asked Questions

Can I hold both FSTSX and OBIOX in my portfolio?

FSTSX and OBIOX have a correlation of 0.83, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FSTSX or OBIOX?

OBIOX has higher volatility (6.50%) compared to FSTSX (4.68%). In terms of maximum drawdown, FSTSX dropped -38.91% vs OBIOX's -71.17%.

Which has better risk-adjusted returns?

FSTSX currently has the higher Sharpe Ratio (1.13 vs 1.07), 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.