The best way to implement this request is to create a Lightning Web Component that can fetch the real-time stock price from an external API and display it on the Account record page. Installing a solution from the AppExchange may not be feasible as it may not match the exact requirements or may have additional costs. Building a Flow that uses API calls may not be efficient as it may consume API limits and may not be able to update the stock price in real-time. Using a scheduled Apex job may not be suitable as it may not be able to run frequently enough to reflect the real-time stock price