Factset has done a beautiful study of the recommendation of Research Houses on which most of the people rely or have to rely (most advisers are compliance bound to take follow it) to make investment choices.
Factset took all data within the last 20 years and got these results
BUY – While generally good performance out of this group, the BUY does show more a behaviour in line with benchmark – not better than benchmark.
Hold – this is the best performing group where some real gems can be found.
Sell – this group generally is true to form, they perform worst than the index.
So, if you want to translate
Research House Action
BUY HOLD
HOLD BUY
SELL SELL
and good luck!!