A trading signal is a mechanism or trigger that is driven by a a strategy in an effort to generate returns from specific securities. A signal can be anything from an event, that changes market participants view of a securities value, to price action, which reflect the supply and demand for a security within the marketplace.
Trading signal are generally designed to meet a specific risk reward criteria that a portfolio manager is looking to achieve. There are two distinct types of trading signals employed by traders in the capital markets. The first is a automated strategies and the second is a discretionary strategies.
Automated Strategies
Automated strategies are generally strategies that have been back tested using historical data. Specific criteria of price action are used to determine if the market mechanism or price action event can foretell future price action. Back testing data is generally driven by using computer programs, that can determine if historical patterns can be profitable based on a risk reward profile.
Designing automated trading strategies start with determining the type of trading strategy the portfolio manager is interested in trading. Many traders feel comfortable trading trends, while other enjoy trading dips and peaks. A trend following trading strategy is one in which a trader looks to follow moving averages or momentum. Two such examples are moving average crossover strategies momentum crossover strategies.
Trend following
A moving average crossover strategy is one in which a trader looks for a short or medium term moving average to cross either above or below a longer term moving average. For example, a trader might look to purchase a security when the 20-day moving average crosses above the 50-day moving average of the security. The reverse would be true for a downward trend. A trader would look to sell a security when the 20-day moving average crosses below the 50-day moving average.
A momentum trading strategy could use a MACD (moving average convergence/divergence index). In this strategy, the difference (the spread) between moving averages (the 12-day moving average and the 26-day moving average) are compared to the 9-day moving average of the spread.
Mean Reversion
Another type of automated strategy is the mean reversion strategy. This type of trading strategy tries to measure how far a security or pair of securities can move from a long term moving average before it bounces back. Many mean reversion strategies use concepts similar to the Bollinger bands which measures an “x” standard deviation from a mean to measure when the proverbial rubber band will snap back.
Discretionary Strategies
Discretionary strategies are concepts that have worked in the past for a trader but do not follow specific iron clad rules to determine when a trading signal is triggered. Discretionary traders will use specific events, including economic data, earnings data, monetary data or political data, along with or without specific types of technical analysis to generate a trading signal.
An example of a event would be an employment report for a specific country or a monetary policy meeting in which new information is release that is current not priced into the market for a specific security.
Discretionary strategies can also employ support and resistance levels that are breached based on subjective trend line variations. Support and resistance levels usually designate price demand and supply, and when breached give way to momentum in the direction of the break out.
Risk Reward
With both automated and discretionary trading signals, the risk that is generated needs to be compensated by the reward received. Back tested results need to show profits based on criteria that do not create the risk of ruin.
Prior to finding a trading signal, a trader should look at the historical track record to determine if the risk taken by the strategy is outweighed by the reward generated by the strategy.