RB vs. SMLL

Last updated Jul 9, 2026

RB (ProShares Russell 2000 Dynamic Daily Buffer ETF) and SMLL (Harbor Active Small Cap ETF) are both exchange-traded funds - RB is a Defined Outcome fund tracking the Russell 2000, while SMLL is a Small Cap Blend Equities fund actively managed by Harbor. RB is passively managed, while SMLL is actively managed. Over the past year, RB returned 18.19% vs -2.75% for SMLL. A 0.59 correlation means they provide meaningful diversification when combined. RB charges 0.58%/yr vs 0.80%/yr for SMLL.

Performance

RB vs. SMLL - Performance Comparison

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

Returns By Period

In the year-to-date period, RB achieves a 7.67% return, which is significantly higher than SMLL's 4.57% return.

RB

• 1D: 0.11%
• 1M: 2.02%
• 6M: 6.22%
• YTD: 7.67%
• 1Y: 18.19%
• 3Y*: —
• 5Y*: —
• 10Y*: —

SMLL

• 1D: -2.49%
• 1M: 2.98%
• 6M: 1.49%
• YTD: 4.57%
• 1Y: -2.75%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

RB vs. SMLL - Yearly Performance Comparison

	2026 (YTD)	2025
RB ProShares Russell 2000 Dynamic Daily Buffer ETF	7.67%	10.85%
SMLL Harbor Active Small Cap ETF	4.57%	-2.93%

Correlation

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

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

Return for Risk

RB vs. SMLL — Risk / Return Rank

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

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

SMLL

SMLL Risk / Return Rank: 7
SMLL Sharpe Ratio Rank: 8
SMLL Sortino Ratio Rank: 7
SMLL Omega Ratio Rank: 7
SMLL Calmar Ratio Rank: 8
SMLL Martin Ratio Rank: 8

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.

RB vs. SMLL - Risk-Adjusted Trends Comparison

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

	RB	SMLL	Difference
Sharpe ratio: Return per unit of total volatility	2.79	-0.16	+2.95
Sortino ratio: Return per unit of downside risk	4.72	-0.10	+4.83
Omega ratio: Gain probability vs. loss probability	1.61	0.99	+0.62
Calmar ratio: Return relative to maximum drawdown	8.74	-0.18	+8.92
Martin ratio: Return relative to average drawdown	28.20	-0.35	+28.56

RB vs. SMLL - Sharpe Ratio Comparison

The current RB Sharpe Ratio is 2.79, which is higher than the SMLL Sharpe Ratio of -0.16. The chart below compares the historical Sharpe Ratios of RB and SMLL, 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

RB vs. SMLL - Drawdown Comparison

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

Drawdown Indicators

	RB	SMLL	Difference
Max Drawdown Largest peak-to-trough decline	-2.09%	-23.56%	+21.47%
Max Drawdown (1Y) Largest decline over 1 year	-2.09%	-15.53%	+13.44%
Current Drawdown Current decline from peak	-0.75%	-9.11%	+8.36%
Average Drawdown Average peak-to-trough decline	-0.45%	-8.71%	+8.26%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.65%	7.76%	-7.11%

Volatility

RB vs. SMLL - Volatility Comparison

The current volatility for ProShares Russell 2000 Dynamic Daily Buffer ETF (RB) is 1.73%, while Harbor Active Small Cap ETF (SMLL) has a volatility of 4.97%. This indicates that RB experiences smaller price fluctuations and is considered to be less risky than SMLL based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RB	SMLL	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.73%	4.97%	-3.24%
Volatility (6M) Calculated over the trailing 6-month period	4.73%	12.13%	-7.40%
Volatility (1Y) Calculated over the trailing 1-year period	6.55%	17.56%	-11.01%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.49%	20.20%	-13.71%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	6.49%	20.20%	-13.71%

RB vs. SMLL - Expense Ratio Comparison

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

Dividends

RB vs. SMLL - Dividend Comparison

RB's dividend yield for the trailing twelve months is around 2.28%, which matches SMLL's 2.27% yield.

Position	TTM	2025	2024
RB ProShares Russell 2000 Dynamic Daily Buffer ETF	2.28%	1.78%	0.00%
SMLL Harbor Active Small Cap ETF	2.27%	2.37%	0.52%

Frequently Asked Questions

Can I hold both RB and SMLL in my portfolio?

RB and SMLL have a correlation of 0.59, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RB or SMLL?

SMLL has higher volatility (4.97%) compared to RB (1.73%). In terms of maximum drawdown, RB dropped -2.09% vs SMLL's -23.56%.

Which ETF is better, RB or SMLL?

On 1-year performance, RB leads with 18.19% vs -2.75% for SMLL. On fees, RB is cheaper at 0.58% per year. On volatility, RB has been the lower-risk option at 1.73%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, RB or SMLL?

Over the 1-year period, RB has performed better with a 18.19% return vs -2.75%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, RB or SMLL?

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

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

RB and SMLL have nearly identical dividend yields, around 2.28%.

What is the main difference between RB and SMLL?

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

Which has better risk-adjusted returns?

RB currently has the higher Sharpe Ratio (2.79 vs -0.16), 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.