The Hang Seng Index is undergoing a dramatic overhaul aimed at giving investors who track it greater exposure to China’s growing technological might. The heavy weighting of financial firms and state-owned enterprises will be reduced, which should go some way to rectifying the Hong Kong benchmark’s serial under-performance, and the near-doubling of the membership will add diversity. The changes aim to better reflect the city’s position as the preferred venue for mainland firms to sell shares, whi