SMLL vs. RB

Last updated Jul 12, 2026

SMLL (Harbor Active Small Cap ETF) and RB (ProShares Russell 2000 Dynamic Daily Buffer ETF) are both exchange-traded funds - SMLL is a Small Cap Blend Equities fund actively managed by Harbor, while RB is a Defined Outcome fund tracking the Russell 2000. SMLL is actively managed, while RB is passively managed. Over the past year, SMLL returned -0.37% vs 18.54% for RB. A 0.59 correlation means they provide meaningful diversification when combined. SMLL charges 0.80%/yr vs 0.58%/yr for RB.

Performance

SMLL vs. RB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Harbor Active Small Cap ETF (SMLL) and ProShares Russell 2000 Dynamic Daily Buffer ETF (RB). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SMLL achieves a 6.05% return, which is significantly lower than RB's 8.28% return.

SMLL

• 1D: 0.23%
• 1M: 1.86%
• 6M: 0.86%
• YTD: 6.05%
• 1Y: -0.37%
• 3Y*: —
• 5Y*: —
• 10Y*: —

RB

• 1D: -0.09%
• 1M: 1.26%
• 6M: 6.00%
• YTD: 8.28%
• 1Y: 18.54%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

SMLL vs. RB - Yearly Performance Comparison

	2026 (YTD)	2025
SMLL Harbor Active Small Cap ETF	6.05%	-2.93%
RB ProShares Russell 2000 Dynamic Daily Buffer ETF	8.28%	10.85%

Correlation

The correlation between SMLL and RB is 0.58, 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	0.58
Correlation (All Time) Calculated using the full available price history since Jun 26, 2025	0.59

The correlation between SMLL and RB has been stable across timeframes, ranging from 0.58 to 0.59 - a consistent structural relationship.

Return for Risk

SMLL vs. RB — Risk / Return Rank

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

SMLL

SMLL Risk / Return Rank: 8
SMLL Sharpe Ratio Rank: 8
SMLL Sortino Ratio Rank: 8
SMLL Omega Ratio Rank: 8
SMLL Calmar Ratio Rank: 8
SMLL Martin Ratio Rank: 8

RB

RB Risk / Return Rank: 96
RB Sharpe Ratio Rank: 94
RB Sortino Ratio Rank: 96
RB Omega Ratio Rank: 95
RB Calmar Ratio Rank: 97
RB Martin Ratio Rank: 96

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.

SMLL vs. RB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Harbor Active Small Cap ETF (SMLL) and ProShares Russell 2000 Dynamic Daily Buffer ETF (RB). 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.

	SMLL	RB	Difference
Sharpe ratio: Return per unit of total volatility	-0.11	2.81	-2.93
Sortino ratio: Return per unit of downside risk	-0.04	4.77	-4.81
Omega ratio: Gain probability vs. loss probability	1.00	1.61	-0.62
Calmar ratio: Return relative to maximum drawdown	-0.13	8.84	-8.97
Martin ratio: Return relative to average drawdown	-0.26	28.52	-28.78

SMLL vs. RB - Sharpe Ratio Comparison

The current SMLL Sharpe Ratio is -0.11, which is lower than the RB Sharpe Ratio of 2.81. The chart below compares the historical Sharpe Ratios of SMLL and RB, 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

SMLL vs. RB - Drawdown Comparison

The maximum SMLL drawdown since its inception was -23.56%, which is greater than RB's maximum drawdown of -2.09%. Use the drawdown chart below to compare losses from any high point for SMLL and RB.

Drawdown Indicators

	SMLL	RB	Difference
Max Drawdown Largest peak-to-trough decline	-23.56%	-2.09%	-21.47%
Max Drawdown (1Y) Largest decline over 1 year	-15.53%	-2.09%	-13.44%
Current Drawdown Current decline from peak	-7.82%	-0.18%	-7.64%
Average Drawdown Average peak-to-trough decline	-8.70%	-0.44%	-8.26%
Ulcer Index Depth and duration of drawdowns from previous peaks	7.77%	0.65%	+7.12%

Volatility

SMLL vs. RB - Volatility Comparison

Harbor Active Small Cap ETF (SMLL) has a higher volatility of 4.79% compared to ProShares Russell 2000 Dynamic Daily Buffer ETF (RB) at 1.82%. This indicates that SMLL's price experiences larger fluctuations and is considered to be riskier than RB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SMLL	RB	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.79%	1.82%	+2.97%
Volatility (6M) Calculated over the trailing 6-month period	12.07%	4.76%	+7.31%
Volatility (1Y) Calculated over the trailing 1-year period	17.58%	6.57%	+11.01%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	20.18%	6.50%	+13.68%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.18%	6.50%	+13.68%

SMLL vs. RB - Expense Ratio Comparison

SMLL has a 0.80% expense ratio, which is higher than RB's 0.58% expense ratio.

Dividends

SMLL vs. RB - Dividend Comparison

SMLL's dividend yield for the trailing twelve months is around 2.23%, less than RB's 2.26% yield.

Position	TTM	2025	2024
RB ProShares Russell 2000 Dynamic Daily Buffer ETF	2.26%	1.78%	0.00%
SMLL Harbor Active Small Cap ETF	2.23%	2.37%	0.52%

Frequently Asked Questions

Can I hold both SMLL and RB in my portfolio?

SMLL and RB have a correlation of 0.58, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, SMLL or RB?

SMLL has higher volatility (4.79%) compared to RB (1.82%). In terms of maximum drawdown, SMLL dropped -23.56% vs RB's -2.09%.

Which ETF is better, SMLL or RB?

On 1-year performance, RB leads with 18.54% vs -0.37% for SMLL. On fees, RB is cheaper at 0.58% per year. On volatility, RB has been the lower-risk option at 1.82%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, SMLL or RB?

Over the 1-year period, RB has performed better with a 18.54% return vs -0.37%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, SMLL or RB?

RB is cheaper with a 0.58% expense ratio, compared with 0.80% for SMLL.

Which ETF pays a higher dividend yield, SMLL or RB?

RB has the higher dividend yield at 2.26%, compared with 2.23% for SMLL.

What is the main difference between SMLL and RB?

SMLL is categorized as Small Cap Blend Equities, while RB is Defined Outcome. They also come from different issuers: Harbor and ProShares. Their fees differ too: 0.80% for SMLL and 0.58% for RB.

Which has better risk-adjusted returns?

RB currently has the higher Sharpe Ratio (2.81 vs -0.11), 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.