I understand that some stock traders try to quickly act on public information to make profits, for example. In the case of scheduled releases of information, however, why do people keep buy or sell orders open during such events? Why doesn't everyone trading that stock stop, read the report, and then resume trading?
The early bird catches the worm. The first person who makes use of the information gains! That is why hedge funds pay billions of dollars to place their routers right at the center of wall street. Moreover, the information is not always correct. The article you are reading may be a rumor spread by someone on wall street.Then there is speculation and that is factored into the price. For example:- In spite of all the bad news from Greece, the market still continued to rise. This was because, everyone had an idea about what was going to happen and the price was factored in way before Greece actually defaulted. The game is way more complicated than it seems. If everyone sat down and read reports, opportunities to make millions of dollars would have been lost in those few seconds. (Please note:- I do not mean reading reports is bad)