If I own x% of company A, and A buys company B, do I own x% of B?
No, thanks to the principle of corporate personhood.  The legal entity (company C) is the owner and parent of the private company (sub S).  You and C are separate legal entities, as are C and S. This principle helps to legally insulate the parties for purposes such as liability, torts, taxes, and so forth.  If company C is sued, you may be financially at stake (i.e. your investment in C is devalued or made worthless) but you are not personally being sued.  However, the litigant may attach you as an additional litigant if the facts of the suit merit it.  But without legal separateness of corporations, then potentially all owners and maybe a number of the employees would be sued any time somebody sued the business - which is messy for companies and messy for litigants.  It's also far cleaner for lenders to lend to  unified business entities rather than a variety of thousands of ever-shifting shareholders. Note that this is a separate analysis that assumes the companies are not treated as partnerships or disregarded entities (tax nothings) for tax purposes, in which case an owner may for some purposes be imputed to own the assets of C.  I've also ignored the consolidated tax return, which would allow C and S to file a type of corporate joint return that for some purposes treats them similarly to common entity. For the simplest variation of your question, the answer is no.  You do not own the assets of a corporation by virtue of owning a few of its shares. Edit:  In light of your edit to include FB and Whatsapp, and the wrinkle about corporate books.  If sub S is 100% owned by company C, then you do not have any inspection rights to S because you are not a shareholder.  You also do not have virtual corporation inspection rights through company C.  However, if a person has inspection rights to company C, and sub S appears on the books and financial records of C, then your C rights will do the job of seeing S information. However, Facebook is a public company, so they will make regular public filings and disclosures that should at least partly cover Whatsapp.  So I hedge and clear my throat by averring that my securities training is limited, but I believe that the SEC filings of a public company will as a practical matter (maybe a matter of law?) moot the inspection rights.  At the very least, I suspect you'd need a proper purpose (under DGCL, for example), to demand the inspection, and they will have already made extensive disclosures that I believe will be presumptively sufficient.  I defer to more experienced securities experts on that question, but I don't believe inspection rights are designed for public companies.