Do I have to fill both I-129 and I-539 for COS from F1 to O1?

[Mcalfo]

Hi,

I am about to send out my I-129 for O1 petition but I am having big doubts about having to send an I-539 with it. I don't have any dependents (everything I find online seems to mention I-539 are required for people with dependents only) and my F1 visa expires in a few days so I am sending the O1 petition ASAP before the F1 expires. So do I need to file both forms (and pay both fees)?
I should add that I am in the US and won't leave the country before I get the answer to the I-129.

Thanks