When something seems too good to be true, it usually is. Many of the trading systems for sale are unprofitable. As well as wasting your money, you could lose your trading capital.

Check these points when looking at a trading system to avoid becoming another victim:

Accuracy

Most trading millionaires use systems that are 50-60% accurate. It is virtually impossible in the real world to get 90% accuracy, but that is what some system vendors claim. As soon as you see that, you know that the figure is not realistic, and may be based on a very limited set of test trades.

Real life performance

It is possible to tweak a trading system to get fabulous results on the right set of test data. You simply adjust it to maximise profit. However it is one thing to do that, and another for it to work in real life. Always check to see whether test results are hypothetical, or whether they have been achieved in actual trading.

A good system should have average losses smaller than average profits.

Disclosure of approach

An undisclosed approach is called a "black box" system. You need a lot of faith to use a system that doesn't state how it works. It is preferable to go for a system that provides some information on the approach used

Longevity

A system that has been around for a while, and has been reviewed and checked out by a number of people (who are not selling it) is preferable to the new kid on the block. Many trading systems spring up, and then quietly disappear once word gets around that they don't work.

Exotic or secret technologies

Innovation is a good thing, but beware of a system vendor who states that their system has some new secret trading approach or includes secret, proprietary approaches used by a hedge fund or investment bank, not previously available.

Iif the system cost millions of dollars for a hedge fund to develop and was truly profitable, would it be for sale for $79.95?

Amount of capital

If the trading system needs $50,000 and you have $1,000, then it is a non starter for you.

Drawdowns

Drawdowns are the maximum negative movement of a trading account. If the system has drawdowns of (say) 30%, you are in for a wild ride, and will need a lot of risk capital. You should be comfortable with the risk factor of the system in real life trading, and this includes the drawdowns.

Practicality

Does the system make hundreds of trades a week, and rely on split second timing? If so, it may not be practical to trade, unless you have some sort of automation to handle the trades. It may not be possible to execute your trades on time if the system relies on very short term movements.

Take care when selecting a trading system - there are a lot of scams out there.