Mass. Gen. Laws ch. 106, § 9-320 – Buyer of Goods

(a) Buyer in ordinary course of business. Except as otherwise provided in subsection (e), a buyer in ordinary course of business, other than a person buying farm products from a person engaged in farming operations, takes free of a security interest created by the buyer's seller, even if the security interest is perfected and the buyer knows of its existence.
(b) Buyer of consumer goods. Except as otherwise provided in subsection (e), a buyer of goods from a person who used or bought the goods for use primarily for personal, family, or household purposes takes free of a security interest, even if perfected, if the buyer buys:
1. (1) without knowledge of the security interest;
2. (2) for value;
3. (3) primarily for the buyer's personal, family, or household purposes; and
4. (4) before the filing of a financing statement covering the goods.
(c) Effectiveness of filing for subsection (b). To the extent that it affects the priority of a security interest over a buyer of goods under subsection (b), the period of effectiveness of a filing made in the jurisdiction in which the seller is located is governed by Sections 9–316(a) and 9–316(b).
(d) Buyer in ordinary course of business at wellhead or minehead. A buyer in ordinary course of business buying oil, gas, or other minerals at the wellhead or minehead or after extraction takes free of an interest arising out of an encumbrance.
(e) Possessory security interest not affected. Subsections (a) and (b) do not affect a security interest in goods in the possession of the secured party under Section 9–313.