As somebody new to trading, I am curious as to how you can construct and test fully automated trading models, first on a training set (historical data) and then on streaming real-time data. I am a computer programmer experienced in the analysis of large data sets and think that statistical modeling of tick-by-tick market data (coupled with companies' financial data) should yield useful information about how to trade profitably in the future. Is there any way to gain access to market data and analytical software with a limited initial investment? I am unwilling to put any significant amount of money up until after I have had an adequate opportunity to develop, test, and simulate various trading models. Also, out of curiosity, how many of you actually sit in front of a computer all day and manually create and execute orders? Do any of you work for hedge funds that employ fully automated trading strategies or has LTCM scared away any likely players in this space? Would you consider yourselves momentum/day traders or hedge fund analysts?