A neural network can only learn from the information available to it.
This makes data quality extremely important.
If training data is incomplete, inaccurate, biased, or irrelevant to current market conditions, the model may learn relationships that are not useful in real trading.
Another challenge is that financial markets evolve.
A pattern that appeared frequently several years ago may become weaker or disappear entirely as market participants, economic conditions, monetary policy, liquidity, and technology change.
This phenomenon is often described as concept drift or changes in the underlying data distribution.
Therefore, building an AI model is not simply a matter of feeding historical prices into a neural network and waiting for it to discover a profitable strategy.
Data selection, model validation, testing, monitoring, and risk controls all matter.