# UNDECLARED_SYMBOL

The strategy reads a symbol it does not list in symbols.

## What happened

A strategy reads the data of a symbol it does not list in `symbols`, so Forge would not have loaded it.

## What to do

Add the symbol to `symbols = [...]`.

## Example

```text
strategy.py, line 38: d["GBPUSD"] reads GBPUSD, which is not in symbols. Add it to symbols = [...]. [UNDECLARED_SYMBOL]
```

The wording of the message depends on your file, and the code does not. An error stops the file from loading.