Alphavantage and NASDAQ Index stopped working

This API call for NASDAQ Composite used to work. Now it returns just an empty JSON. {}. No error message.

https://www.alphavantage.co/query?function=TIME_SERIES_MONTHLY&symbol=IXIC&apikey=your_api_key

Other indices seem to work OK eg DJI, SPX

An email to support has not been answered.

Anyone have any more information on this?

Solution

UPDATE

The trick below has stopped working. Hopefully Alpha Vantage will regain their access to the NASDAQ soon.

Try replacing IXIC with NASDAQ:^IXIC