SEM vs. VOO

Last updated Aug 1, 2026

SEM (Select Medical Holdings Corporation) is a stock, while VOO (Vanguard S&P 500 ETF) is S&P 500 fund tracking the S&P 500 Index. Their 0.45 correlation means their historical movements had little consistent relationship.

Performance

SEM vs. VOO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Select Medical Holdings Corporation (SEM) and Vanguard S&P 500 ETF (VOO). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

SEM

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

VOO

• 1D: 0.71%
• 1M: 0.26%
• 6M: 8.58%
• YTD: 10.16%
• 1Y: 21.58%
• 3Y*: 19.42%
• 5Y*: 12.83%
• 10Y*: 15.14%
• ALL TIME*: 14.78%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
VOO Vanguard S&P 500 ETF	$3.82B	$3.78B	$5.44B

SEM vs. VOO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SEM Select Medical Holdings Corporation	12.07%	-19.84%	51.24%	-3.52%	-13.85%	7.41%	18.51%	52.05%	-13.03%	33.21%
VOO Vanguard S&P 500 ETF	10.16%	17.82%	24.98%	26.32%	-18.17%	28.79%	18.32%	31.37%	-4.50%	21.77%

Correlation

The correlation between SEM and VOO is 0.16, which is low. Their historical price movements had little consistent relationship.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.16
Correlation (3Y) Balances recent behavior with more history.	0.37
Correlation (5Y) Shows whether the relationship held over a longer period.	0.44
Correlation (10Y) Provides a long-term view across more market conditions.	0.46
Correlation (All Time) Calculated using the full available price history since Sep 9, 2010	0.45

Over the past year, the correlation between SEM and VOO has dropped to 0.16 - well below their long-term average of 0.45, suggesting their price drivers have been diverging.

Return for Risk

SEM vs. VOO — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

SEM

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

VOO

VOO Risk / Return Rank: 68
VOO Sharpe Ratio Rank: 68
VOO Sortino Ratio Rank: 65
VOO Omega Ratio Rank: 66
VOO Calmar Ratio Rank: 64
VOO Martin Ratio Rank: 76

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

SEM vs. VOO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Select Medical Holdings Corporation (SEM) and Vanguard S&P 500 ETF (VOO). 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.

	SEM	VOO	Difference
Sharpe ratio: Return per unit of total volatility	—	1.53	—
Sortino ratio: Return per unit of downside risk	—	2.13	—
Omega ratio: Gain probability vs. loss probability	—	1.28	—
Calmar ratio: Return relative to maximum drawdown	—	2.21	—
Martin ratio: Return relative to average drawdown	—	9.44	—

Drawdowns

Drawdown Indicators

	SEM	VOO	Difference
Max Drawdown Largest peak-to-trough decline	—	-33.99%	—
Max Drawdown (1Y) Largest decline over 1 year	—	-8.90%	—
Max Drawdown (3Y) Largest decline over 3 years	—	-18.69%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-24.52%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-33.99%	—
Current Drawdown Current decline from peak	—	-1.38%	—
Average Drawdown Average peak-to-trough decline	—	-3.67%	—
Ulcer Index Depth and duration of drawdowns from previous peaks	—	2.08%	—

Volatility

Volatility by Period

	SEM	VOO	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	3.54%	—
Volatility (6M) Calculated over the trailing 6-month period	—	10.10%	—
Volatility (1Y) Calculated over the trailing 1-year period	—	12.82%	—
Volatility (5Y) Calculated over the trailing 5-year period, annualized	—	16.93%	—
Volatility (10Y) Calculated over the trailing 10-year period, annualized	—	18.01%	—

Dividends

SEM vs. VOO - Dividend Comparison

SEM has not paid dividends to shareholders, while VOO's dividend yield for the trailing twelve months is around 1.07%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
SEM Select Medical Holdings Corporation	1.51%	1.68%	97.39%	2.13%	2.01%	1.28%	0.00%	0.00%	0.00%	0.00%	0.00%	0.84%
VOO Vanguard S&P 500 ETF	1.07%	1.13%	1.24%	1.46%	1.69%	1.25%	1.54%	1.88%	2.06%	1.78%	2.02%	2.10%

Frequently Asked Questions

Can I hold both SEM and VOO in my portfolio?

SEM and VOO have a correlation of 0.16, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.