Definition:
A hub and spoke structure is an investment structure used by an investment firm in which several investment vehicles, each remaining individually managed, pool their assets together, contributing to one central investment vehicle. this can also be known as a master-feeder structure. All of the funds within the system generally have the same investment objective. The smaller investment vehicles are referred to as the “spokes.” The central investment vehicle is referred to as the “hub” or the master fund.
Further Reading:
Book: Writing Effective Use cases by Alistair Cockburn.