(March 1): Hang Seng Indexes Co plans what will be one of the biggest revamps to Hong Kong’s 51-year-old stock benchmark, a move that will affect tens of billions of dollars in funds tracking it.

The wide-ranging overhauls to the Hang Seng Index include increasing the number of constituents to 80 companies from 52 and limiting a stock’s weighting to 8%, the firm said in a statement on Monday. Implementation of the changes will begin as early as its May index review and go through mid-2022.