OPOCX vs. OBMCX

Last updated Jun 4, 2026

OPOCX (Invesco Discovery Fund) and OBMCX (Oberweis Micro Cap Fund) are both Small Cap Growth Equities funds. Over the past 10 years, OPOCX returned 16.53%/yr vs 21.63%/yr for OBMCX. Their correlation of 0.85 suggests significant overlap in exposure. OPOCX charges 1.01%/yr vs 1.48%/yr for OBMCX.

Performance

OPOCX vs. OBMCX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Invesco Discovery Fund (OPOCX) and Oberweis Micro Cap Fund (OBMCX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, OPOCX achieves a 30.98% return, which is significantly lower than OBMCX's 45.67% return. Over the past 10 years, OPOCX has underperformed OBMCX with an annualized return of 16.53%, while OBMCX has yielded a comparatively higher 21.63% annualized return.

OPOCX

• 1D: 2.40%
• 1M: 5.92%
• YTD: 30.98%
• 6M: 31.47%
• 1Y: 56.26%
• 3Y*: 26.88%
• 5Y*: 10.85%
• 10Y*: 16.53%

OBMCX

• 1D: 2.91%
• 1M: 3.70%
• YTD: 45.67%
• 6M: 45.60%
• 1Y: 77.10%
• 3Y*: 29.76%
• 5Y*: 19.97%
• 10Y*: 21.63%

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

OPOCX vs. OBMCX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
OPOCX Invesco Discovery Fund	30.98%	16.77%	22.61%	17.02%	-31.26%	14.78%	50.33%	36.81%	-4.15%	29.04%
OBMCX Oberweis Micro Cap Fund	45.67%	14.70%	22.82%	18.87%	-10.57%	53.20%	29.91%	21.94%	-12.04%	27.90%

Correlation

The correlation between OPOCX and OBMCX is 0.86, 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	0.86
Correlation (3Y) Calculated over the trailing 3-year period	0.89
Correlation (5Y) Calculated over the trailing 5-year period	0.90
Correlation (10Y) Calculated over the trailing 10-year period	0.89
Correlation (All Time) Calculated using the full available price history since Jun 4, 1996	0.85

The correlation between OPOCX and OBMCX has been stable across timeframes, ranging from 0.85 to 0.90 - a consistent structural relationship.

Return for Risk

OPOCX vs. OBMCX — Risk / Return Rank

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

OPOCX

OPOCX Risk / Return Rank: 71
OPOCX Sharpe Ratio Rank: 67
OPOCX Sortino Ratio Rank: 53
OPOCX Omega Ratio Rank: 51
OPOCX Calmar Ratio Rank: 93
OPOCX Martin Ratio Rank: 93

OBMCX

OBMCX Risk / Return Rank: 90
OBMCX Sharpe Ratio Rank: 94
OBMCX Sortino Ratio Rank: 83
OBMCX Omega Ratio Rank: 78
OBMCX Calmar Ratio Rank: 96
OBMCX Martin Ratio Rank: 97

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.

OPOCX vs. OBMCX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Invesco Discovery Fund (OPOCX) and Oberweis Micro Cap Fund (OBMCX). 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.

	OPOCX	OBMCX	Difference
Sharpe ratio Return per unit of total volatility	2.39	3.24	-0.85
Sortino ratio Return per unit of downside risk	3.07	3.90	-0.83
Omega ratio Gain probability vs. loss probability	1.39	1.51	-0.12
Calmar ratio Return relative to maximum drawdown	5.12	6.47	-1.35
Martin ratio Return relative to average drawdown	20.36	25.98	-5.61
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

OPOCX vs. OBMCX - Sharpe Ratio Comparison

The current OPOCX Sharpe Ratio is 2.39, which is comparable to the OBMCX Sharpe Ratio of 3.24. The chart below compares the historical Sharpe Ratios of OPOCX and OBMCX, 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

	OPOCX	OBMCX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.39	3.24	-0.85
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.43	0.77	-0.34
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.67	0.84	-0.17
Sharpe Ratio (All Time) Calculated using the full available price history	0.51	0.45	+0.06

Drawdowns

OPOCX vs. OBMCX - Drawdown Comparison

The maximum OPOCX drawdown since its inception was -64.17%, smaller than the maximum OBMCX drawdown of -68.24%. Use the drawdown chart below to compare losses from any high point for OPOCX and OBMCX.

Drawdown Indicators

	OPOCX	OBMCX	Difference
Max Drawdown Largest peak-to-trough decline	-64.17%	-68.24%	+4.07%
Max Drawdown (1Y) Largest decline over 1 year	-11.38%	-12.45%	+1.07%
Max Drawdown (3Y) Largest decline over 3 years	-28.60%	-28.11%	-0.49%
Max Drawdown (5Y) Largest decline over 5 years	-43.27%	-28.11%	-15.16%
Max Drawdown (10Y) Largest decline over 10 years	-43.27%	-50.04%	+6.77%
Current Drawdown Current decline from peak	-0.18%	0.00%	-0.18%
Average Drawdown Average peak-to-trough decline	-18.87%	-16.42%	-2.45%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.85%	3.09%	-0.24%

Volatility

OPOCX vs. OBMCX - Volatility Comparison

Invesco Discovery Fund (OPOCX) and Oberweis Micro Cap Fund (OBMCX) have volatilities of 7.85% and 8.26%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OPOCX	OBMCX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.85%	8.26%	-0.41%
Volatility (6M) Calculated over the trailing 6-month period	20.07%	18.66%	+1.41%
Volatility (1Y) Calculated over the trailing 1-year period	24.38%	24.89%	-0.51%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	25.39%	26.20%	-0.81%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	24.85%	25.88%	-1.03%

OPOCX vs. OBMCX - Expense Ratio Comparison

OPOCX has a 1.01% expense ratio, which is lower than OBMCX's 1.48% expense ratio.

Dividends

OPOCX vs. OBMCX - Dividend Comparison

OPOCX's dividend yield for the trailing twelve months is around 10.24%, more than OBMCX's 0.97% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OBMCX Oberweis Micro Cap Fund	0.97%	1.41%	2.53%	0.00%	1.37%	24.35%	0.00%	0.00%	19.67%	11.76%	0.05%	3.07%
OPOCX Invesco Discovery Fund	10.24%	13.41%	6.86%	0.00%	0.00%	20.51%	11.22%	6.42%	18.85%	12.46%	4.33%	6.84%

Frequently Asked Questions

Can I hold both OPOCX and OBMCX in my portfolio?

OPOCX and OBMCX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, OPOCX or OBMCX?

OBMCX has higher volatility (8.26%) compared to OPOCX (7.85%). In terms of maximum drawdown, OPOCX dropped -64.17% vs OBMCX's -68.24%.

Which has better risk-adjusted returns?

OBMCX currently has the higher Sharpe Ratio (3.24 vs 2.39), 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.