A career in banking and finances, whether it is in investment banking, private equity, asset management, etc, requires a wide range of skills, alongside of course deep financial knowledge. This combination of skills and knowledge can absolutely be beneficial to you when working in a political career.
Financial knowledge would make you suited to working in positions which are centered on economics, markets and similar. Through your knowledge of how capital moves, shifts in market dynamics, accounting and auditing, etc, you would be better suited to apply this specialised knowledge in roles where such knowledge is necessary in ensuring the best outcomes. Therefore, you would be able to guide and direct policy with greater accuracy, for example when looking to eliminate legal loopholes.
You can apply mathematical and statistical techniques to your work, particularly work involving research and data analysis. As in finances you would be required to use a range of mathematical and statistical techniques, these can be applied to when you may need to work with datasets, raw data, or economic statistics.
You would already have some understanding of legislation and policy through legal and regulatory compliance. This knowledge would carry over to politics as you would have an idea how policy is implemented and its subsequent effects.
Strong communication skills, including with a range of stakeholders. This is vital in politics, as you will be in contact with a diverse range of different groups. You will be required to ensure amicable and effective communication, eliminating possibilities of potential miscommunications arising.