The function downloads IPO data provided by Jay
R. Ritter https://site.warrington.ufl.edu/ritter.
Since the data are provided in Excel format, package
openxlsx is required.
The downloaded Excel gets a date prefix (today in
format YYYYMMDD
) and is stored in directory
dest.dir
. Before any download is attempted,
the function checks whether a file with today's
prefix exist in dest.dir
; if yes, this file is
used.