@togr still I doubt that marketmakers use an EAs for trading. That outbalances all the trades that EAs execute at the moment.
An automated trading system (ATS) is a computer trading program that automatically submits trades to an exchange. Automated trading systems are often used with other forms of electronic trading, such as electronic communication network, 'dark pools' and algorithmic trading. As of the year 2010 more than 70% of the stock shares traded on the NYSE and NASDAQ are generated from automated trading systems. They are designed to trade stocks, futures and forex based on a predefined set of rules which determine when to enter a trade, when to exit it and how much to invest in it.Trading strategies come in many different shapes and sizes, some preferring to pick market tops and bottoms, others coded to ride the daily trend, and everything in between. 
Algorithmic trading may be used in any investment strategy, including market making, inter-market spreading, arbitrage, or pure speculation (including trend following). The investment decision and implementation may be augmented at any stage with algorithmic support or may operate completely automatically. One of the main issues regarding HFT is the difficulty in determining how profitable it is. A report released in August 2009 by the TABB Group, a financial services industry research firm, estimated that the 300 securities firms and hedge funds that specialize in this type of trading took in a maximum of US$21 billion in profits in 2008, which the authors called 'relatively small' and 'surprisingly modest' when compared to the market's overall trading volume. In March 2014, Virtu Financial, a high-frequency trading firm, reported that during five years it made profit 1,277 out of 1,278 days, losing money just one day.
@togr : Yes, good definition (albeit direct from Wikipedia!). I totally agree - still surprising how many people underestimate the (real) potential of algorithmic (automated) trading. But then, I guess we are in a forum... and only certain people hang out in a forum (the 90% of losing traders). 'It is impossible to soar like an eagle when you hang out with chickens.' My question is: where do the 'eagles' hang out? 😉
Despite the very real and evidenced potential of computers for executing trades automatically, I seriously do not think MQL5 are smart enough to do something like Big Brother (heck, MQL5 keep messing things up - can they do anything right?)
Excellent point about eagles and chickens. The reality is the internet (especially sites like these) are filled with mostly untalented traders. If in reality we had some serious talent here, then we would have someone who can keep his or her drawdown% and Pip - drawdown DOWN, and keep the profits coming in, how ever much profit it is.
Yet, we want to feel as if we can predict the future and we say things like the market is over bought or under sold, and look to take positions that way, when the reality is the market doesn't move based on over or under anything. If simply looked at th market for what it is 'supply and demand' then trading would be so much easier.
Think about the very first minute of forex being public..... How did the price shift either upward or downward, if there were no HIgher TF to come by? In forex if you believe the chicken came before the egg or visa versa will determine your perception of how the market works, your perception of the market will determine your bias, and your bias will determine how quickly you margin call.
So until you so called GURUS stop margin calling accounts, and stop having 300+ pip draw down, then your simply taking educated guesses, instead of rational ones. Stick to the damm script, and learn how to read the lower tf. Lower TF's create what you see on the higher TF. We think fundamentals run the market, when all it does is create bias. Simply ask the people who have been buying UJ the last week, and buying everytime it goes up. Oh won't their Christmas holiday be much brighter if they were not in red over 500 pips.