Automated trading are use on forex trading, stock markets and mutual funds. These trading make up over 20% of the trading perform world wide according to wikipedia.com and its growing trend is continue to show in the many years to come.
Computerised automated trading begin as early as 1970s where stock market are converting to electronics trading from paper trading and it has growth tremendously. This makes trading effectively and manageable across a global market.
There are few strategies besides executing trades base on human inputs. The more common ones are trend following, hedging, channel trading, scalping, martingale, support and resistance trading.
Trend following These are commonly used with averaging volume indicator like simple moving average, relative strength index and a combination of moving average using different timeframe or various average length. Common used are 9, 18 and 40 simple moving average, 20 and 80 relative strength index, etc
Hedging This strategy is similar to hedge fund where trades are buy and sell to counter value the loss and profit. Common hedging are United State Dollar with Great Britain Pound, United State Dollar with Canadian Dollar, Swiss Franc with Australian Dollar, Euro with United States Dollar.
Channel trading This trading watches the hourly or daily high and low and execute trades when reaches the low and high range. It will look like a bouncing ball where the price will go up and down bouncing like a ball.
Scalping strategy This is more commonly used in Forex trading where small amount of profits or PIPS are taken from every trades and cumulative profit from many of these small trades. The risk is high but volume of trades will compensate its loss.
Martingale This originates from mathematics arithmetic calculation where the lots quantity will increase with increasing losses. This is a sure win strategy in theory but in practical it is very difficult to achieve due to large capital that is required to maintain the margin.
Support and resistance trading This is the fundament used in trading as it is believe trading price and traders will see support level and resistance level through out the whole duration of trading. The support and resistance can be divergence or convergence, thus makes many combination of support and resistance that can be obtained when looking at multiple timeframe.
MT4 and Tradestation are 2 main trading software widely used for Forex automated trading. Forex trading involved risk and you are to fully understand them before trading any of the commercial products.