I have a df which looks like:
Let the group name of the individual columns be 'Symbol', so that a list of column names 'Symbol' = ['AAPL US Equity', 'ABT US Equity', 'BDX US Equity', 'BRO US Equity'] Let 'Returns' be the floats. Let 'Dates' be a datetime index.
Question: I need the df to have MultiIndex of ['Ticker', 'Dates'] with the hierarchy of it being the order i.e. 'Ticker' --> 'Dates' --> 'Returns'
Something like:
It is first grouped by 'Symbol', then by 'Date'

