In case you were wondering why most stocks were green yesterday and $AAPL, $MSFT, $GOOG and $AMZN were down, here's why 👇

The Nasdaq 100 index will be rebalanced to reduce the heavy weighting of the few companies in the index, according to the announcement. In response, stocks of companies like Apple, Microsoft, Amazon and Alphabet have dropped 1-2% as their weight in the index will likely be reduced. The changes will be made on July 24.

Rebalancing usually occurs for several reasons:

- Maintaining the proper representation of companies in the index.

- Limiting the influence of individual firms. No one firm should make up too large a portion of the index.
- Adherence to a predetermined methodology. The indexes have clearly defined rules for selecting and weighting firms that must be followed.¨

- Minimizing costs for investors. Rebalancing allows investors to hold portfolios replicating the index without the need for daily intervention.