smallcases are reviewed & updated on a regular basis. You can see the next expected update date on the smallcase page under the Stocks & Weights tab

This is done to ensure the stocks & weights in the smallcase continue to reflect the underlying theme and strategy

When a smallcase you hold has been rebalanced, you receive a Rebalance Update notification for the same via e-mail

All aspects of rebalancing are explained in detail in a dedicated section. Read All Rebalancing FAQs