Product
The settle fee
Buyers send 100%. Sellers receive 87.5%. The book keeps 12.5%.
Settled sells pay the seller 87.5% of quoted SOL. The book keeps 12.5%. Buyers still send 100% of quoted SOL and receive 100% APU. The fee is not hidden in the APU size.
Fee basis points come from the quote — 1250 bps by default. Every live offer and every lock screen shows the four amounts before you commit.
Treasury cash-out on Econext is a different clock and a different fee story. Do not mix those settlement sentences when you size an ask.