On February 1, 2019, Borrower borrows $5,000 from Bank 1 pursuant to a note that is repayable on July 1, 2019, and grants Bank 1 a security interest in its store equipment. A security agreement is executed. However, due to a mistake at Bank 1, a financing statement is not filed until April 1, 2019.

On March 1, 2019, Borrower borrows $5,000 from Bank 2, also pursuant to a note that is repayable on July 1, 2019, and grants Bank 2 a security interest in the same collateral, its store equipment. A security agreement is executed and a financing statement is filed on March 2, 2019.

When Borrower defaults on both loans, which Bank has priority and why?