PortfoliosLab logoPortfoliosLab logo

Documentation

Upgrade your plan
SIZE vs. VO
Performance
Return for Risk
Drawdowns
Volatility
Dividends

SIZE vs. VO

Last updated Jun 4, 2026

SIZE (iShares MSCI USA Size Factor ETF) and VO (Vanguard Mid-Cap ETF) are both Mid Cap Blend Equities funds - SIZE tracks the MSCI USA Low Size Index while VO tracks the CRSP US Mid Cap Index. Both are passively managed. Over the past 10 years, SIZE returned 11.76%/yr vs 11.55%/yr for VO. Their correlation of 0.90 suggests significant overlap in exposure. SIZE charges 0.15%/yr vs 0.03%/yr for VO.

Performance

SIZE vs. VO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares MSCI USA Size Factor ETF (SIZE) and Vanguard Mid-Cap ETF (VO). The values are adjusted to include any dividend payments, if applicable.

Loading charts...

Returns By Period

In the year-to-date period, SIZE achieves a 9.07% return, which is significantly lower than VO's 10.05% return. Both investments have delivered pretty close results over the past 10 years, with SIZE having a 11.76% annualized return and VO not far behind at 11.55%.

SIZE

1D
-0.68%
1M
3.62%
YTD
9.07%
6M
8.29%
1Y
18.11%
3Y*
15.94%
5Y*
8.07%
10Y*
11.76%

VO

1D
-0.45%
1M
3.20%
YTD
10.05%
6M
9.73%
1Y
18.13%
3Y*
16.69%
5Y*
7.87%
10Y*
11.55%
*Multi-year figures are annualized to reflect compound growth (CAGR)

SIZE vs. VO - Yearly Performance Comparison

2026 (YTD)202520242023202220212020201920182017
SIZE
iShares MSCI USA Size Factor ETF		9.07%10.51%14.37%17.78%-15.86%25.05%16.26%28.97%-6.59%18.76%
VO
Vanguard Mid-Cap ETF		10.05%11.62%15.31%16.03%-18.73%24.70%18.10%30.98%-9.24%19.28%

Correlation

The correlation between SIZE and VO is 0.94, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

Correlation
Correlation (1Y)
Calculated over the trailing 1-year period

0.94

Correlation (3Y)
Calculated over the trailing 3-year period

0.97

Correlation (5Y)
Calculated over the trailing 5-year period

0.98

Correlation (10Y)
Calculated over the trailing 10-year period

0.96

Correlation (All Time)
Calculated using the full available price history since Apr 19, 2013

0.90

The correlation between SIZE and VO has been stable across timeframes, ranging from 0.90 to 0.98 - a consistent structural relationship.

SIZE vs. VO - Sectors Allocation Comparison

Sectors
SIZE
VO

Technology

19.9%
18.6%

Industrials

16.1%
17.9%

Financial Services

13.5%
12.8%

Consumer Cyclical

9.8%
8.6%

Healthcare

9.6%
7.6%

Real Estate

5.7%
5.4%

Consumer Defensive

5.7%
4.8%

Utilities

5.5%
8.3%

Energy

5.2%
8.5%

Basic Materials

4.8%
4.2%

Communication Services

4.1%
3.1%

Technology

SIZE
19.9%
VO
18.6%

Industrials

SIZE
16.1%
VO
17.9%

Financial Services

SIZE
13.5%
VO
12.8%

Consumer Cyclical

SIZE
9.8%
VO
8.6%

Healthcare

SIZE
9.6%
VO
7.6%

Real Estate

SIZE
5.7%
VO
5.4%

Consumer Defensive

SIZE
5.7%
VO
4.8%

Utilities

SIZE
5.5%
VO
8.3%

Energy

SIZE
5.2%
VO
8.5%

Basic Materials

SIZE
4.8%
VO
4.2%

Communication Services

SIZE
4.1%
VO
3.1%

Compare stocks, funds, or ETFs

Search for stocks, ETFs, and funds for a quick comparison or use the comparison tool for more options.

iShares MSCI USA Size Factor ETF

Vanguard Mid-Cap ETF

Often compared with SIZE:
SIZE vs. XLGSIZE vs. SPYSIZE vs. QUALSIZE vs. QDVA.DESIZE vs. VIGSIZE vs. VOOSIZE vs. QGRO
Often compared with VO:
VO vs. VOOVO vs. VOTVO vs. IJHVO vs. VOEVO vs. VIMAXVO vs. VXFVO vs. SCHM

Return for Risk

SIZE vs. VO — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.
SIZE
SIZE Risk / Return Rank: 4444
Overall Rank
SIZE Sharpe Ratio Rank: 4040
Sharpe Ratio Rank
SIZE Sortino Ratio Rank: 4242
Sortino Ratio Rank
SIZE Omega Ratio Rank: 3838
Omega Ratio Rank
SIZE Calmar Ratio Rank: 4646
Calmar Ratio Rank
SIZE Martin Ratio Rank: 5252
Martin Ratio Rank
VO
VO Risk / Return Rank: 4343
Overall Rank
VO Sharpe Ratio Rank: 4141
Sharpe Ratio Rank
VO Sortino Ratio Rank: 4141
Sortino Ratio Rank
VO Omega Ratio Rank: 3838
Omega Ratio Rank
VO Calmar Ratio Rank: 4444
Calmar Ratio Rank
VO Martin Ratio Rank: 5050
Martin Ratio Rank
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.

SIZE vs. VO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares MSCI USA Size Factor ETF (SIZE) and Vanguard Mid-Cap ETF (VO). 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.

SIZEVODifference
Sharpe ratioReturn per unit of total volatility
1.43
1.48

-0.05

Sortino ratioReturn per unit of downside risk
2.12
2.14

-0.01

Omega ratioGain probability vs. loss probability

1.25

1.26

-0.01

Calmar ratioReturn relative to maximum drawdown

2.28

2.23

+0.05

Martin ratioReturn relative to average drawdown

8.88

8.50

+0.38

Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SIZE vs. VO - Sharpe Ratio Comparison

The current SIZE Sharpe Ratio is 1.43, which is comparable to the VO Sharpe Ratio of 1.48. The chart below compares the historical Sharpe Ratios of SIZE and VO, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Loading charts...

Sharpe Ratios by Period

SIZEVODifference

Sharpe Ratio (1Y)

Calculated over the trailing 1-year period

1.43

1.48

-0.05

Sharpe Ratio (5Y)

Calculated over the trailing 5-year period

0.47

0.45

+0.02

Sharpe Ratio (10Y)

Calculated over the trailing 10-year period

0.63

0.61

+0.02

Sharpe Ratio (All Time)

Calculated using the full available price history

0.68

0.50

+0.18

Drawdowns

SIZE vs. VO - Drawdown Comparison

The maximum SIZE drawdown since its inception was -39.15%, smaller than the maximum VO drawdown of -58.87%. Use the drawdown chart below to compare losses from any high point for SIZE and VO.

Loading charts...

Drawdown Indicators

SIZEVODifference

Max Drawdown

Largest peak-to-trough decline

-39.15%

-58.87%

+19.72%

Max Drawdown (1Y)

Largest decline over 1 year

-7.97%

-8.17%

+0.20%

Max Drawdown (3Y)

Largest decline over 3 years

-18.71%

-19.02%

+0.31%

Max Drawdown (5Y)

Largest decline over 5 years

-24.03%

-27.57%

+3.54%

Max Drawdown (10Y)

Largest decline over 10 years

-39.15%

-39.37%

+0.22%

Current Drawdown

Current decline from peak

-0.68%

-0.45%

-0.23%

Average Drawdown

Average peak-to-trough decline

-4.18%

-7.86%

+3.68%

Ulcer Index

Depth and duration of drawdowns from previous peaks

2.04%

2.14%

-0.10%

Volatility

SIZE vs. VO - Volatility Comparison

iShares MSCI USA Size Factor ETF (SIZE) has a higher volatility of 3.17% compared to Vanguard Mid-Cap ETF (VO) at 2.99%. This indicates that SIZE's price experiences larger fluctuations and is considered to be riskier than VO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Loading charts...

Volatility by Period

SIZEVODifference

Volatility (1M)

Calculated over the trailing 1-month period

3.17%

2.99%

+0.18%

Volatility (6M)

Calculated over the trailing 6-month period

9.54%

9.21%

+0.33%

Volatility (1Y)

Calculated over the trailing 1-year period

12.73%

12.34%

+0.39%

Volatility (5Y)

Calculated over the trailing 5-year period, annualized

17.39%

17.59%

-0.20%

Volatility (10Y)

Calculated over the trailing 10-year period, annualized

18.69%

18.95%

-0.26%

SIZE vs. VO - Expense Ratio Comparison

SIZE has a 0.15% expense ratio, which is higher than VO's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

SIZE vs. VO - Dividend Comparison

SIZE's dividend yield for the trailing twelve months is around 1.42%, more than VO's 1.36% yield.

PositionTTM20252024202320222021202020192018201720162015
SIZE
iShares MSCI USA Size Factor ETF		1.42%1.50%1.53%1.42%1.59%1.19%1.43%1.35%2.43%1.58%1.88%1.95%
VO
Vanguard Mid-Cap ETF		1.36%1.52%1.49%1.52%1.60%1.12%1.45%1.48%1.82%1.35%1.45%1.47%

Frequently Asked Questions

With a correlation of 0.94, SIZE and VO move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

SIZE has higher volatility (3.17%) compared to VO (2.99%). In terms of maximum drawdown, SIZE dropped -39.15% vs VO's -58.87%.

On 10-year performance, SIZE leads with 11.76% vs 11.55% for VO. On fees, VO is cheaper at 0.03% per year. On volatility, VO has been the lower-risk option at 2.99%. The better choice depends on whether you care most about return, fees, risk, or income.

Over the 10-year period, SIZE has performed better with a 11.76% return vs 11.55%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

VO is cheaper with a 0.03% expense ratio, compared with 0.15% for SIZE.

SIZE has the higher dividend yield at 1.42%, compared with 1.36% for VO.

SIZE tracks MSCI USA Low Size Index, while VO tracks CRSP US Mid Cap Index. They also come from different issuers: iShares and Vanguard. Their fees differ too: 0.15% for SIZE and 0.03% for VO.

VO currently has the higher Sharpe Ratio (1.48 vs 1.43), 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.

Portfolio Optimizer

Find the right allocation for SIZE and VO

Add both to a portfolio and optimize allocations for your target — whether that's maximizing returns, minimizing drawdowns, or balancing risk across holdings.

Open Portfolio Optimizer