The basis amount that results from adjusting the gross basis for net carry. Net carry is the actual coupon income of a bond in addition to its re-investment minus borrowing costs (which are calculated at the money market repo rate). A positive net basis reflects the net cost that a long cash/ short futures position would incur, while it reflects the expected gain for the short cash/ long futures position (where the actual repo rate is the reverse repo rate). The net basis is given by:

Where P_d is the bond dirty price, r is the repo rate, Del is the days to delivery, P_fut is the futures price, CF is the conversion factor, and AI_del is the accrued interest to delivery.

The net basis represents the true economic basis. Brokerage firms usually quote bonds on a net basis, i.e., the price quoted to investors includes a mark-up in lieu of a commission.