`data` from OnData is called but only contains empty stock.

Hello Bryson,

In QuantConnect, when a stock changes its ticker symbol, the data associated with the old symbol will not be updated to the new symbol. This is because the data is associated with the specific symbol at the time it was collected.

However, QuantConnect provides an event handler OnSymbolChangedEvents that provides information on ticker changes. This can be used to handle such situations in your algorithm. Here is an example of how to use it in Python:

def on_symbol_changed_events(self, symbol_changed_events: SymbolChangedEvents) -> None:
    for symbol, symbol_changed_event in symbol_changed_events.items():
        pass

In this example, symbol_changed_events is a dictionary where the key is the old symbol and the value is the new symbol. You can use this to update your data variable when a symbol change occurs.

Also, it's a good practice to check if the data for a symbol exists before accessing it. You can do this by using an if statement like this:

if data[self.symbol] is None:
    return

This will prevent your algorithm from throwing an error when the data for a symbol is None.

Sources:

• Handling Data
• Forum Discussion