For a long time now we have struggled to cope with the sheer volumeof responses we get to debates on the Have Your Say index - around 10, 000 e-mails a day.
These data are available through a site called Google Trends, which allows anyone who cares to do so to download an indexofthe aggregate volumeof searches for particular terms or categories.
Mann also noted that ETF market makers are participating in equity markets freshly rebuilt on volume-based incentives, not exactly the kind of bait that would attract long-term holders in passive index investments.
The recent increase in volume is accompanied by an explosion in volatility: The CBOE Nasdaq Volatility Index, reflecting short-term expectations of volatility in the Nasdaq 100 Index, surged to 80 from 20 or so between mid-2006 and October of last year.