On the market pulse

For the man behind the Hang Seng Index, quiet trading days are the worst. That is because no movement in the index could mean a glitch in the system.

"When there is a quiet market and the index hasn't changed for a few minutes, I start to worry if there is anything wrong with the calculation of the index," said Vincent Kwan Wing-shing, a director and general manager of Hang Seng Indexes.

On the other hand, Kwan is little worried if there is volatile trading, when the index can move hundreds or thousands of points a day.

The index, which dates back to 1964, has chronicled the roller-coaster ride of the markets, from the record low of 58.61 points on August 31, 1967 - triggered by riots - to the historical high of 31,638.22 on October 30, 2007 - just before the start of the global financial crisis.

The biggest fall was triggered by the so-called "Black Monday" stock market crash of 1987, when the index plunged 33.33 per cent on October 26 that year. The biggest one-day rise was on October 29, 1997, when it soared 18.82 per cent.

Today, the investing public takes the index for granted, perhaps not realising that more than 1,000 derivatives products or index funds are linked to it.