Offer - A proposed stated sale price or price range for whole loans or securities.

Open space - A largely undeveloped area of land or water dedicated for public or private use.

Open-end fund - A commingled fund that accepts new investors' capital, does not have predetermined end date, makes new property investments, and sells underperforming investments.

Operating cost escalation - Escalation clauses are intended, through a variety of ways, to adjust rents by external reference standards such as a published index, negotiated wage levels, or ownership and operation expenses of a building.

Operating expense - Actual costs associated with using a property, such as maintenance and repairs, management, taxes, utilities and insurance.

Opportunistic - A phrase generally describing investments in underperforming and/or under sub par managed assets that have an expectation of near-term increases in cash flow and value.

Originator - A company specializing in the creation and underwriting of commercial and residential mortgage loans.

Out-parcel - Individual retail site of each business in a shopping center or mall.

Overallotment - When an underwriter offers to sell more shares than it has agreed to buy from the share's issuer.