Are accounts signed only when buying not selling?

I’ve had an account for a while which has been dormant for several months. I pretty much only sell BTC. Today I sold BTC as a taker from a signed account but am still unsigned. In truth it doesn’t make a huge difference to me personally since my sell limit is high but because i sell a lot I think it would benefit the ecosystem if I were signed. do I need to make a purchase from a signed account to get signed?

Signature is for payment methods with higher risk of chargeback, so yeah, as BTC seller your account won’t be signed.