Use 5 cells to reference to the values in the other five workbooks. The
write a formula that checks the status of those 5 cells. I am not sure what
your possible values are but as an example:

The 5 cells could return the other workbook's cell's values or FALSE if not
found. Then your formula could count how many times FALSE appears in the 5
cells (use COUNTIF). If the COUNTIF formula returns 5 then you could display
"UP" or ""

=IF(COUNTIF($B$1:$B$5,"=FALSE")=5,"UP","DOWN")