Technology are applied everywhere in today's stock market including transactions, analysis, information, etc. The information about the stock market flows much faster than ever. Benefit from the technology improvement, the shortening of the period between a trade being initiated and complete, or the reduction of latency as it is known, is the ultimate aim of any stock exchange worth its salt.
Basically two ways:
Simple economics (supply and demand)
Yes.
In automated trading milliseconds make a difference.
With algorithms trading, latency in getting price information is a big deal since price changes from time to time in milliseconds.
IPO - ¥610,000/share ($5041/share) of J-COM Trader wanted to sell 1 share at ¥610,000 Instead placed order to sell 610,000 shares at ¥1 each Loss to bank was 3 months profits J-COM ended up being 1/3 owned by Merrill Lynch Tokyo stock exchange lost 1.72%
Trader placed order typing ‘b’ instead of ‘m’ (billion vs. million) for number of shares Share price dropped $61.56 → $39.37 in 20 minutes NYSE dropped 600 points in 20 minutes (and recovered though still off almost 400 points for the day)
http://www.huffingtonpost.com/2012/04/18/mark-gorton-high-frequency-trading_n_1429935.html
The question at the heart of the current debate about high-frequency trading is whether the automation of trading – and in Tower's case, the ability to maximize profits by executing trades faster than anyone else – really does make the world better.
http://www.huffingtonpost.com/robert-auerbach/has-computer-trading-made_b_819664.html
Retail investors should also consider Jim McTague's advice about short-term stock trading: “It has become a shark tank and we are the anchovies.”
For every technique or technology that comes under the heading of HFT, you can dig up an example of how people did this same thing on a much smaller scale without computers. Therefore, the argument goes, the relatively recent (see below) use of computers to do two orders of magnitude more of these activities in a given timeslice is “nothing new,” despite the fact that the computers are now doing this among themselves without human intervention.
http://prairieecothrifter.com/2011/08/major-problem-modern-day-stock-market.html
Investors should have learned this from the stock market crash in 2008, that there is a major flow in the modern stock markets. That flaw lies in computer algorithms and trading.