When sizing your market consider what is appropriate, fits to your business model and make use of primary and secondary research. It is also useful to consider tactical information versus your strategic direction.
Looking at the bigger picture first and then analysing the details of smaller components (downwards funnel).
Focuses on the analysis of individual stocks and deemphasises the significance of economic cycles and market cycles (upwards funnel).
It is useful to conduct both a top down and a bottom up analysis of the market, however, you should use your bottom up analysis when presenting the business. The bottom up method is more specific and will be viewed as more credible. We recommend you present your bottom up figures.
Total Addressable/Available Market (TAM)
Total market demand for a product or service
Segmented/Serviceable Addressable Market (SAM)
Segment of the total market (TAM) targeted by your products and services within your reach
Segmented/Serviceable Obtainable Market (SOM) Short Term
Portion of the serviceable addressable market (SAM) the company can capture