Dropping a minor

Based on the most helpful WSO content, it's generally not necessary to inform the bank about dropping a minor, especially if it doesn't affect your major or the skills relevant to your internship. Here are some key points to consider:

• Relevance to the Job: If the minor in Mathematical Finance is not directly relevant to the tasks you'll be performing during your internship, the bank is unlikely to be concerned about it.
• Focus on Performance: Banks are more interested in your performance and the skills you bring to the table rather than the specifics of your academic coursework.
• Professionalism: Avoid unnecessary emails that might come off as trivial. Bankers have numerous responsibilities, and such details might not be significant to them.

In summary, unless the minor was a critical part of your offer or significantly impacts your qualifications, there's no need to email the bank about dropping it. Focus on excelling in your major and preparing for your internship.

Sources: CS Interns - Resist the temptation to email a banker/staff to ask about your internship, Dear Interns: Don't e-mail the CEO, 5 Steps To Becoming A Rockstar Freshman (Undergrad Advice), How to Obtain a Sophomore Summer Boutique IB Internship, Should I delay graduation by a semester for a summer internship at a large bank?