Sure, but market share and company size are two fundamentally different problems.
Measuring the size of a company is a lot easier: you pick some metric (employees, revenue, profit, customers, etc...) and apply it to all companies.
Measuring market share requires that you categorize all companies into "markets," which think is pretty subjective. Is Jet Brains an IDE company? A software company? How about Apple? If multiple, are metrics split?
Whatever rules you pick, they're going to be biased towards some companies (including some big ones not popular on HN) and against other companies (including some companies HN loves).
