Portfolio lenders are usually Savings & Loan institutions, and sometimes banks. They are called "portfolio" lenders because they tend to originate loans for their own portfolio (usually adjustable rate loans), not for resale in the secondary market. The distinction gets blurred because most portfolio lenders also engage in mortgage banking.
They will often pay more compensation to their loan officers for originating a portfolio product than for originating a fixed rate loan. You may also find that they are not as competitive as mortgage bankers and brokers in the fixed rate loan market, though this is no longer a hard and fast rule.
It is often easier to qualify for a portfolio loan, so they are often a lender of "second resort" for those who cannot qualify for a fixed rate loan. If a loan officer is steering you towards "sub-prime" loans, it might be wise to check out a portfolio lender first.
