Earlier quoted context omitted.
Yea no I'm also left scratching my head. I've never heard of a methodology to attribute market cap portions to business units; eager to hear some clarification too.
It is a well-established concept called https://www.investopedia.com/terms/s/sumofpartsvaluation.asp . A company's value is estimated on net present value (npv) of its projected, discounted future cash flows. If a company has a large, stable subsidiary that is growing slowly but is cash flow positive and a very fast growing but money losing subsidiary, it makes more sense to value parent company as if both subsidiari…
Typically in mergers, you see accretion due to the removal of duplicate functions on the cost side (you don’t need two HR departments for example), but sometimes you get negative credit if you’re a too big / too opaque / too confusing.