I think researches on trading systems is the main issue of building trading strategies. Our main goal is to build a strategy, which will be successful in the future and not only on backtests (curve-fitting). Thatis why I consider it right to start the topic with the description of the two approaches to the creation of trading strategies.
Momentum is one of the simplest and most popular indicators among traders. As its creator, certain sources name a French mathematician Paul Émile Appell. This indicator helps define the trend direction and the speed of the price change.