Systems go through the following lifecycle:

• Inception
• Creation
• Testing
• Implementation
• Production Trading
• Monitoring
• Suspension
• Retirement

Each step will now be described.

Inception

First we must have an idea:  A testable hypothesis about how a tradable instrument will perform under certain circumstances.  The accuracy of the predictions made by the hypothesis do not have to be 100%, or even 75%, but better than 50% is a good starting point.

Examples include:

• Stocks tend to have carry-through on large intra-day moves
• Certain markets over-gap on good or bad news and then reverse in the opposite direction of the gap

Creation

Once we have our hypothesis we can create a complete trading system that implements the idea.  The trading system will include all the elements outlined previously in the 'Our Systems' section of this web site.

Testing

Each trading system goes through 3 phases of testing before it can be introduced as a new production trading system.

Phase 1 is historical testing of the idea back at least 1000 trades, or 1000 days, whichever spans the longest time.  Although previous performance of a trading system is no guarantee of future success, systems that have never worked in the past are unlikely to start working in the future.

If the expectancy (average winner/average loser) of the system is not positive in historical testing it is discarded as a false hypothesis.  If the system has a very negative expectation we may reverse the original hypothesis and continue to Phase 2 testing.  Occasionally the hypothesis may be modified and re-tested, although it is better to view this as a new system test.

Phase 2 is the testing of the system for at least 30 real-time trades on paper, recording trades as if they were real.  If, at the end of this period, the expectancy closely matches the historical expectancy, then we can proceed to phase 3.  If the expectancy does not match the one from Phase 1, we can continue with Phase 2 testing for another set of 30 trades.  If we continue to get a negative expectancy for the paper-trading we will discard the system at this point.

Phase 3 testing involves trading the system with small lots to ensure that we can really achieve the entry and exit prices estimated by our historical and paper trading.  If, after 30 trades we still have a positive expectancy, then the new system can be implemented in production.

Implementation

If a system passes successfully through the 3 testing phases, it can be implemented in the production trading environment.  The system will be allocated a portion of the trading account, and each entry signal that is generated by the system will be traded.  Implementation includes a formal definition of the system, automation of the trade entry signals, and daily monitoring of positions.

Production Trading

The system is traded in production as long as it has a positive expectancy, and is not temporarily suspended by any of the rules that govern when the system can be traded.

Monitoring

Each production system is monitored daily, weekly, and monthly, to ensure it is operating within the expected parameters, and does not need to be temporarily suspended, or permanently retired.

Suspension

Some systems have rules that determine periods when they should be temporarily suspended.  Also, if the expectancy of a system tends towards zero (break even) then we will suspend it in production and revert to paper trading until the expectancy goes back to the historical norm, or the system is retired.

Retirement

If the expectancy of a system goes to, or below, zero, and does not recover after paper-trading for a statistically significant amount of trades it will be permanently retired.  Occasionally poor performance is due to the omission of a rule that would temporarily suspend the system during certain periods of time.  If this is the case the system may be re-implemented with new rules and go back through the whole testing process again.