I am looking to get time series for certain delisted tickers. For the common shares, I can use RIC with with the month and year of delisting, and that works. For the warrants, I am not getting the delisted tickers in this format. Instead, I only see ___.DEX (e.g. ACTTW.DEX).
When I get the time series for these, it is usually very incomplete, has a shortened range. Does anyone know why this might be and how to fix this issue?