How to define the TAM, SAM, SOM for a SaaS (I will not promote)

Hi! I will not promote I'm currently trying to define the TAM, SAM, SOM for a pitch deck. It's an asset tracking app and I plan to focus my go-to-market strategy on crypto users although the solution could be used to track traditional assets too. For the TAM I've found a report estimating the global crypto ownership to 562M users. Then I multiplied that number with my Annual Contract Value. Now I'm struggling with the SAM. I was wondering if considering the crypto owners in my country would make sense for a SaaS. Technically, anyone in the world could have access to the app online. I was thinking it might be easier to get early traction within my geographical area as the country is quite pro-crypto. For the SOM I've been told to consider 1-10% of the SAM. What do you think?