For generations of Hong Kong investors, Hang Seng Bank was never just a stock. The Hang Seng Index , the city’s undisputed financial barometer, now no longer contains Hang Seng Bank. Founded in 1933 as a modest money-changing business in Sheung Wan, Hang Seng Bank grew alongside the city’s improbable rise. In 1965, a banking panic triggered a run on deposits, and Hang Seng Bank lost a sixth of its holdings in a single day. For many customers, walking into a Hang Seng branch felt like coming home.