Backtesting is a kind of a strategy test performed on the past data. It can be either automated or manual. For automated backtesting, a special software should be coded. Automated testing is more precise but requires a fully mechanical trading system to test. Manual testing is slow and can be rather inaccurate, but requires no extra programming and can be done without any special preparation process. Any backtesting results should be taken with a grain of salt as the tested strategy might have been created to fit particular backetsting historical data.
Fair Value strategy made use of in various financial markets. In the forex market, the fair value of a currency is determined based on the economic situation in a country. In order to use this forex strategy, traders must have an understanding about a few basic related to the economy, especially the GDP growth of the two economies whose currencies they plan to buy and sell. Other aspects to be considered include the unemployment rate and the inflation data.