California lien position basics
A deed of trust secures a loan against real property. When more than one loan is recorded against the same property, they have an order of priority — usually by recording date. That order is the lien position, and it determines who gets paid first if the property is sold or foreclosed.
A 1st deed of trust is the senior loan: first in line to be repaid. A 2nd deed of trust (a junior lien) sits behind the first and is only repaid after the senior loan is satisfied. The more subordinate the position, the more risk the lender takes — which is why private capital evaluates a 2nd differently from a 1st.
Private capital evaluates a 1st on loan-to-value (LTV) and a 2nd on combined loan-to-value (CLTV), because the existing first loan still has to be repaid ahead of the new money. A common alternative to stacking a 2nd is a new 1st that pays off the existing first and delivers the requested proceeds in a single senior loan.