There are various different types of expert advisors such as the following:

News Expert Advisors are designed to take advantage of the large price movements that can occur on and after the release of important fundamental data that could influence the markets.

Breakout Expert Advisors open new trades when the market price breaks through predefined support and resistance levels.

Hedge Expert Advisors trade both buy and sell positions within the same currency with the intent of minimizing the loss on one while maximizing the profit on the other.

Scalper Expert Advisors are used in many popular Forex robots. The general idea behind any scalping method of trading is to reduce risk by getting into a trade and then out as quickly as possible thereby limiting risk exposure by limiting the time a trader is exposed. This is repeated a large number of times for a small low-risk gain each time. One of the main ideas of this strategy is to attack the markets during their off hours when they have settled into a tight predictable range pattern. The time period selected is between 9.00 pm and 1.00 am GMT and only the following currency pairs are traded: EUR/GBP, EUR/CHF, GBP/CHF, USD/CAD. Europe, UK, Switzerland, USA and Canada do not release any national fundamental data during this time period and as such the Forex can be very quiet with low volatility thereby making for a low margin but safe trading.

Traditional Expert Advisors that were used previously had a more static design and always used the same initial configuration of settings from the outset. As they could not readily adjust to changes in market, they were unable to optimize their own win : loss ratio and expectancy values.

Adaptive Expert Advisors are relatively new and have more ability than their predecessors to modify their trading performances, depending on market conditions, to achieve maximum profits. The new adaptive expert advisors are capable of perceiving their environment, categorizing it and then using the resulting information to make adjustments to their own operations with the purpose of achieving higher profitability at minimum risk.

Expert Advisors for MetaTrader4 (MT-4) are all unique and follow different rules to enter and exit the market. The advantage of using them is that they eliminate the emotional trading decisions that novices are prone to. Everything will be based on logic. They provide Forex traders with a strict system working on pre-programmed parameters that will prevent them from trading beyond fixed boundaries. And being robots, designed specifically for this purpose, they can evaluate more parameters more quickly than the human mind can.

The MQL-4 programming language used for the MT-4 platform makes it easy to use all the technical indicators available in a variety of ways, as desired by the user. MQL-4 is short for Meta Quotes Language version 4. MetaTrader 4 is a free trading platform developed by MetaQuotes Software Corporation and supported by many different Forex brokers all over the world. MetaTrader 4 is easy to learn and very user-friendly. One of the unique qualities of MetaTrader 4 is its ability to automate trading activities through the use of an expert advisor. Multiple instances of an expert advisor can be operated on the same MetaTrader4 client terminal, as long as they are all compatible.