I am working with data from Kenneth French Data library. While I am aware that they use simple returns, I remain unsure about their format in downloadable files.
This is an extract of the file "Portfolios formed on Book to Market" showing daily portfolio returns based on their Book to Market ratio.
I do not see it anywhere if the values are simple returns in absolute terms (1.37=137%), or in percentages (i.e. 1.37%).