There is a variant of grep that supports this feature for large sets of strings, try
fileWithListOfSearchTargets=myFileOfSearchTargets.txt
fgrep -f ${fileWithListOfSearchTargets} file1 file2 ... filen
(The variable and filenames are meant to be self-documenting, you can use any name you like)
You have to enter all your search strings into the file.
No leading or trailing spaces unless you expect those to match in your filelist.
There is a limit to the size that most fgreps can process. Don't try to cram 10K lines into one file.
I hope this helps.
P.S. as you appear to be a new user, if you get an answer that helps you please remember to mark it as accepted, and/or give it a + (or -) as a useful answer.