Indices Compared

Two funds in a portfolio are not the same as two investments. A world ETF plus an S&P 500 ETF means holding many of the same companies a second time, at a heavier weight. What a second fund adds comes down to four questions, none of which is enough on its own:

Overlap: how much weight sits in the same companies?
Correlation: do the prices move together anyway?
Risk: does one swing harder than the other?
Cost: what does the cheapest fund on each index charge?

Every page here computes all four from our holdings and price data.

Indices Compared
Comparison	Overlap	Correlation
S&P 500 or MSCI USA	96.5%	–
MSCI World Information Technology or MSCI USA Information Technology	90.8%	–
MSCI Europe or STOXX Europe 600	89.4%	–
MSCI World or MSCI World IMI	86.0%	–
MSCI World or MSCI ACWI	85.9%	0.99
MSCI ACWI or MSCI ACWI IMI	79.2%	–
MSCI Emerging Markets or MSCI EM IMI	74.9%	1.00
MSCI World Health Care or MSCI USA Health Care	73.6%	–
MSCI World or MSCI USA	72.2%	–
MSCI World or MSCI ACWI IMI	72.1%	–
MSCI World or S&P 500	70.3%	0.98
MSCI World Consumer Staples or MSCI USA Consumer Staples	66.8%	–
MSCI World Financials or MSCI USA Financials	54.0%	–
S&P 500 or Nasdaq 100	52.6%	0.95
Nasdaq 100 or MSCI USA Information Technology	51.6%	–
Nasdaq 100 or S&P 500 Information Technology	51.2%	0.97
Nasdaq 100 or MSCI World Information Technology	49.5%	–
MSCI Europe or MSCI EMU	49.0%	0.96
MSCI World or MSCI World Quality	41.4%	–
MSCI World or Nasdaq 100	37.8%	0.93
S&P 500 or S&P 500 Information Technology	36.1%	0.89
MSCI USA or MSCI USA Information Technology	35.8%	–
MSCI Europe or Euro STOXX 50	34.3%	0.95
DAX or Euro STOXX 50	29.7%	0.92
S&P 500 or Dow Jones	29.5%	0.89
MSCI World or MSCI World Momentum	29.3%	–
MSCI World or MSCI World Minimum Volatility	29.1%	–
MSCI World or MSCI World Information Technology	28.3%	–
MSCI World Quality or MSCI World Momentum	25.4%	–
MSCI World or MSCI World ex USA	24.8%	0.86
MSCI World or MSCI World SRI	24.6%	–
MSCI Emerging Markets or MSCI China	20.6%	0.64
MSCI World or MSCI Europe	15.7%	0.80
MSCI World or MSCI World Value	15.6%	–
MSCI World or STOXX Europe 600	15.1%	–
MSCI Europe or DAX	14.2%	0.91
DAX or STOXX Europe 600	13.2%	–
MSCI ACWI or MSCI Emerging Markets	11.0%	0.81
MSCI World or MSCI EMU	7.7%	0.81
MSCI World or MSCI Japan	5.4%	0.79
MSCI World Value or MSCI World Quality	5.2%	–
MSCI World or DAX	2.2%	0.76
MSCI Europe or MSCI Europe Small Cap	0.0%	–
MSCI World or MSCI Emerging Markets	0.0%	0.75
MSCI World or MSCI World Small Cap	0.0%	–
S&P 500 or Euro STOXX 50	0.0%	0.71
S&P 500 or MSCI Emerging Markets	0.0%	0.69
S&P 500 or MSCI World ex USA	0.0%	0.76
S&P 500 or Russell 2000	0.0%	0.85
S&P 500 or STOXX Europe 600	0.0%	–

Sorted by overlap. A high value means the two indices sit largely in the same companies.