Thirty days on a GMX short

On GMX, when does a short start paying the borrow fee?

• When funding turns negative
• When shorts become the side with the larger open interest
• From the moment it opens, whatever the open interest

A market uses a linear borrow model with a 50% tier. Utilisation is 40%. What is the yearly borrow rate?

• 50%
• 40%
• 20%