Official Comment §8-1502

3. The following examples illustrate the operation of Section 8-502.

Example 4. Debtor holds XYZ Co. shares in a securities account with Able & Co. As collateral for a loan from Bank, Debtor grants Bank a security interest in the security entitlement to the XYZ Co. shares. Bank perfects by a method which leaves Debtor with the ability to dispose of the shares. See Section 9-115 9-312 [Maine cite section 9-1312]. In violation of the security agreement, Debtor sells the XYZ Co. shares and absconds with the proceeds. Assume - implausibly - that Bank is able to trace the XYZ Co. shares and show that the "same shares" ended up in Buyer's securities account with Baker & Co. Section 8-502 precludes any action by Bank against Buyer, whether framed in constructive trust or other theory, provided that Buyer acquired the security entitlement for value and without notice of adverse claims.

Example 6.__Debtor grants Alpha Co. a security interest in a security entitlement that includes 1000 shares of XYZ Co. stock that Debtor holds through an account with Able & Co.__Alpha also has an account with Able.__Debtor instructs Able to transfer the shares to Alpha, and Able does so by crediting the shares to Alpha's account.__Alpha has control of the 1000 shares under Section 8-106(d).__(The facts to this point are identical to those in Section 8-106, Comment 4, Example 1, except that Alpha Co. was Alpha Bank.)__Alpha next grants Beta Co. a security interest in the 1000 shares included in Alpha's security entitlement.__See Section 9-207(c)(3)[Maine cite section 9-1207, subsection (3), paragraph (c)].__Alpha instructs Able to transfer the shares to Gamma Co., Beta's custodian.__Able does so, and Gamma credits the 1000 shares to Beta's account.__Beta now has control under Section 8-106(d).__By virtue of Debtor's explicit permission or by virtue of the permission inherent in Debtor's creation of a security interest in favor of Alpha and Alpha's resulting power to grant a security interest under Section 9-207 [Maine cite section 9-1207]. Debtor has no adverse claim to assert against Beta, assuming implausibly that Debtor could "trace" an interest to the Gamma account.__Moreover, even. if Debtor did hold an adverse claim, if Beta did not have notice of Debtor's claim, Section 8-502 will preclude any action by Debtor against Beta, whether framed in constructive trust or other theory.