RMBBX vs. OBMCX

Last updated Jun 24, 2026

RMBBX (RMB Small Cap Fund) and OBMCX (Oberweis Micro Cap Fund) are both Small Cap Growth Equities funds. Their correlation of 0.85 suggests significant overlap in exposure. RMBBX charges 1.06%/yr vs 1.48%/yr for OBMCX.

Performance

RMBBX vs. OBMCX - Performance Comparison

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

Returns By Period

RMBBX

• 1D: —
• 1M: —
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

OBMCX

• 1D: 1.48%
• 1M: 8.34%
• YTD: 52.27%
• 6M: 47.81%
• 1Y: 81.13%
• 3Y*: 30.63%
• 5Y*: 20.28%
• 10Y*: 22.47%

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

RMBBX vs. OBMCX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
RMBBX RMB Small Cap Fund	7.65%	-0.06%	15.10%	18.71%	-24.78%	24.32%	17.62%	27.51%	-5.47%	10.48%
OBMCX Oberweis Micro Cap Fund	52.27%	14.70%	22.82%	18.87%	-10.57%	53.20%	29.91%	21.94%	-12.04%	27.90%

Correlation

The correlation between RMBBX and OBMCX is 0.65, 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	0.65
Correlation (3Y) Calculated over the trailing 3-year period	0.80
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (10Y) Calculated over the trailing 10-year period	0.86
Correlation (All Time) Calculated using the full available price history since Sep 4, 2002	0.85

The correlation between RMBBX and OBMCX shifts across timeframes, from 0.65 (1 year) to 0.86 (10 years), reflecting how their relationship changes across market environments.

Return for Risk

RMBBX vs. OBMCX — Risk / Return Rank

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

RMBBX

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

OBMCX

OBMCX Risk / Return Rank: 92
OBMCX Sharpe Ratio Rank: 96
OBMCX Sortino Ratio Rank: 87
OBMCX Omega Ratio Rank: 83
OBMCX Calmar Ratio Rank: 97
OBMCX Martin Ratio Rank: 98

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.

RMBBX vs. OBMCX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for RMB Small Cap Fund (RMBBX) 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.

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.

	RMBBX	OBMCX	Difference
Sharpe ratio: Return per unit of total volatility	—	3.23	—
Sortino ratio: Return per unit of downside risk	—	3.83	—
Omega ratio: Gain probability vs. loss probability	—	1.50	—
Calmar ratio: Return relative to maximum drawdown	—	6.77	—
Martin ratio: Return relative to average drawdown	—	26.80	—

Drawdowns

Drawdown Indicators

	RMBBX	OBMCX	Difference
Max Drawdown Largest peak-to-trough decline	—	-68.24%	—
Max Drawdown (1Y) Largest decline over 1 year	—	-12.45%	—
Max Drawdown (3Y) Largest decline over 3 years	—	-28.11%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-28.11%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-50.04%	—
Current Drawdown Current decline from peak	—	0.00%	—
Average Drawdown Average peak-to-trough decline	—	-16.39%	—
Ulcer Index Depth and duration of drawdowns from previous peaks	—	3.14%	—

Volatility

Volatility by Period

	RMBBX	OBMCX	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	10.03%	—
Volatility (6M) Calculated over the trailing 6-month period	—	20.16%	—
Volatility (1Y) Calculated over the trailing 1-year period	—	26.14%	—
Volatility (5Y) Calculated over the trailing 5-year period, annualized	—	26.41%	—
Volatility (10Y) Calculated over the trailing 10-year period, annualized	—	26.01%	—

RMBBX vs. OBMCX - Expense Ratio Comparison

RMBBX has a 1.06% expense ratio, which is lower than OBMCX's 1.48% expense ratio.

Dividends

RMBBX vs. OBMCX - Dividend Comparison

RMBBX's dividend yield for the trailing twelve months is around 6.38%, more than OBMCX's 0.93% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OBMCX Oberweis Micro Cap Fund	0.93%	1.41%	2.53%	0.00%	1.37%	24.35%	0.00%	0.00%	19.67%	11.76%	0.05%	3.07%
RMBBX RMB Small Cap Fund	6.38%	5.98%	2.15%	5.62%	2.75%	6.44%	4.38%	4.73%	45.44%	21.23%	3.70%	9.34%

Frequently Asked Questions

Can I hold both RMBBX and OBMCX in my portfolio?

RMBBX and OBMCX have a correlation of 0.65, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.