The seemingly unstoppable growth of megacaps like Apple Inc. and Microsoft Corp. mean they have breached an upper limit imposed on stocks in the Nasdaq 100.

• As a result, Nasdaq Inc. has announced a “special rebalance” — the first ever of its kind — will be carried out to redistribute the weight of the index’s members.
• The index provider says the July 24 adjustment will “address overconcentration in the index by redistributing the weights.”

Click here to read more about the rebalance.