I spent some time in the Crimea many years ago, and brought home some lovely nesting dolls, what are called Matryoshka, similar to the ones pictured below. These dolls are hollow, and rest inside each other.
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Corporately, a nesting doll structure is one in which a series of public companies own large stakes in each other, before finally getting to an operating asset. This isn't a structure I'm particularly fond of, because the usual reason for it is to control an asset without having an economic interest that justifies that control.
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