ARB vs. ^GSPC

Last updated Apr 2, 2026

Compare and contrast key facts about AltShares Merger Arbitrage ETF (ARB) and S&P 500 Index (^GSPC).

ARB is a passively managed fund by Water Island Capital Partners LP that tracks the performance of the Water Island Merger Arbitrage USD Hedged Index. It was launched on May 7, 2020.

Performance

ARB vs. ^GSPC - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in AltShares Merger Arbitrage ETF (ARB) and S&P 500 Index (^GSPC). The values are adjusted to include any dividend payments, if applicable.

ARB vs. ^GSPC - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
ARB AltShares Merger Arbitrage ETF	0.91%	6.05%	4.07%	3.85%	2.67%	3.16%	3.78%
^GSPC S&P 500 Index	-3.95%	16.39%	23.31%	24.23%	-19.44%	26.89%	30.37%

Returns By Period

In the year-to-date period, ARB achieves a 0.91% return, which is significantly higher than ^GSPC's -3.95% return.

ARB

• 1D: 0.05%
• 1M: 0.56%
• YTD: 0.91%
• 6M: 1.52%
• 1Y: 4.55%
• 3Y*: 5.52%
• 5Y*: 4.13%
• 10Y*: —

^GSPC

• 1D: 0.72%
• 1M: -4.45%
• YTD: -3.95%
• 6M: -2.02%
• 1Y: 16.73%
• 3Y*: 16.96%
• 5Y*: 10.34%
• 10Y*: 12.24%

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

Return for Risk

ARB vs. ^GSPC — Risk / Return Rank

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

ARB

ARB Risk / Return Rank: 88
ARB Sharpe Ratio Rank: 82
ARB Sortino Ratio Rank: 86
ARB Omega Ratio Rank: 81
ARB Calmar Ratio Rank: 93
ARB Martin Ratio Rank: 96

^GSPC

^GSPC Risk / Return Rank: 67
^GSPC Sharpe Ratio Rank: 63
^GSPC Sortino Ratio Rank: 64
^GSPC Omega Ratio Rank: 69
^GSPC Calmar Ratio Rank: 60
^GSPC Martin Ratio Rank: 77

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.

ARB vs. ^GSPC - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for AltShares Merger Arbitrage ETF (ARB) and S&P 500 Index (^GSPC). 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.

	ARB	^GSPC	Difference
Sharpe ratio Return per unit of total volatility	1.64	0.92	+0.73
Sortino ratio Return per unit of downside risk	2.38	1.41	+0.97
Omega ratio Gain probability vs. loss probability	1.33	1.21	+0.11
Calmar ratio Return relative to maximum drawdown	3.59	1.41	+2.17
Martin ratio Return relative to average drawdown	17.51	6.61	+10.90
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

ARB vs. ^GSPC - Sharpe Ratio Comparison

The current ARB Sharpe Ratio is 1.64, which is higher than the ^GSPC Sharpe Ratio of 0.92. The chart below compares the historical Sharpe Ratios of ARB and ^GSPC, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	ARB	^GSPC	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.64	0.92	+0.73
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.95	0.61	+0.33
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.68	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.95	0.46	+0.49

Correlation

The correlation between ARB and ^GSPC is 0.38, which is considered to be low. This implies their price changes are not closely related. A low correlation is generally favorable for portfolio diversification, as it helps to reduce overall risk by spreading it across multiple assets with different performance patterns.

Drawdowns

ARB vs. ^GSPC - Drawdown Comparison

The maximum ARB drawdown since its inception was -5.60%, smaller than the maximum ^GSPC drawdown of -56.78%. Use the drawdown chart below to compare losses from any high point for ARB and ^GSPC.

Drawdown Indicators

	ARB	^GSPC	Difference
Max Drawdown Largest peak-to-trough decline	-5.60%	-56.78%	+51.18%
Max Drawdown (1Y) Largest decline over 1 year	-1.20%	-12.14%	+10.94%
Max Drawdown (5Y) Largest decline over 5 years	-5.60%	-25.43%	+19.83%
Max Drawdown (10Y) Largest decline over 10 years	—	-33.92%	—
Current Drawdown Current decline from peak	0.00%	-5.78%	+5.78%
Average Drawdown Average peak-to-trough decline	-0.96%	-10.75%	+9.79%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.25%	2.60%	-2.35%

Volatility

ARB vs. ^GSPC - Volatility Comparison

The current volatility for AltShares Merger Arbitrage ETF (ARB) is 0.86%, while S&P 500 Index (^GSPC) has a volatility of 5.37%. This indicates that ARB experiences smaller price fluctuations and is considered to be less risky than ^GSPC based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	ARB	^GSPC	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.86%	5.37%	-4.51%
Volatility (6M) Calculated over the trailing 6-month period	2.01%	9.55%	-7.54%
Volatility (1Y) Calculated over the trailing 1-year period	2.79%	18.33%	-15.54%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.37%	16.90%	-12.53%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.41%	18.05%	-13.64%