Clarification of Answer by
31 Jan 2004 17:56 PST
The trend is, quite simply, a result of the stock exchange rules
mentioned above. The NYSE and AMEX operate under rules that specify
that 'free' stock ticker updates must be delayed by 20 minutes; the
NASDAQ rules specify that 'free' ticker updates for their exchange
must be delayed by 15 minutes.
Television stations and websites that subscribe to this 'free' ticker
update feed, are required to inform their viewers that the values are
delayed values. The easiest way is to simply say "quotes delayed by at
least 15 minutes" for NASDAQ stock symbols, and "quotes delayed by at
least 20 minutes" when displaying quotes for NYSE, AMEX, and NASDAQ
combined. The values of 15 and 20 minutes are set by the exchanges,
and are simply to allow them to sell real-time and less-delayed quote
feeds for a higher price than the 'free' delayed quote feeds. There's
a pretty big business in supplying fast quote feeds, as you can
probably well imagine.
If you are interested in learning more about the history behind this,
you may want to post another Question along the lines of "when did
delayed stock ticker feeds become available from the New York Stock
Exchange?", or "how have stock quote ticker feeds evolved over the
last 100 years?". Please note, though, that such a Question will
require much more research than a typical $2 Question, so you will
need to price it accordingly. Probably only advisable if you have a
deep-rooted interest in this topic!
Hope this helps!
Google Answers Researcher