When should I say welcome?

As a cryptocurrency and finance professional, I'm often asked about the appropriate times to greet clients or business associates. So, let me pose the question to you: When is it most appropriate to say 'welcome'? Is it at the beginning of a meeting, when someone new joins a project, or perhaps after a successful transaction? Understanding the context and tone of the situation is key. Do you think it's more important to be formal or informal when welcoming someone? How does your greeting affect the overall atmosphere and the perception of your professionalism? Let's discuss the nuances of when and how to properly say 'welcome' in the world of cryptocurrency and finance.