xargs doesn't pass its arguments to the shell, it directly invokes exec: $ echo 'test $(foo bar) test' | xargs echo test $(foo bar) test $ ec

xargs doesn't pass its arguments to the shell, it directly invokes exec: $ echo 'test $(foo bar) test' | xargs echo test $(foo bar) test $ echo 'test $(foo bar) test' | xargs python -c 'print(len(__import__("sys").argv))' 5 the $ and ( are nothing special to xargs, nor to echo (or wget). Not to say yay xargs is always great, just that this specific counter example doesn't hold up.