State Street Investment Management’s Oct. 20 index table puts the combined published weights of the 10 biggest holdings at 38.44%.
NVIDIA Corporation had the highest index weight at 7.89%, followed by Apple at 7.46% and Microsoft at 5.95%. Alphabet appeared twice: Its Class A and Class C shares held separate positions. The top 10 therefore represented nine companies.
The S&P 500 weights companies by the market value of shares available for public trading, S&P Dow Jones Indices says. That method gives larger members more influence over index moves.
The S&P 500 Equal Weight Index uses a different rule: Each company receives a 0.2% weight at quarterly rebalances, according to S&P Dow Jones Indices. Holdings weights alone cannot establish which stocks drove a difference in returns.
