Fund may refer to:
In United States tax law, a section 475(f) fund is a hedge fund that elects to mark to market all its unrealized gains and losses, as allowed by the provisions of section 475(f) of the Internal Revenue Code. This can lead to a much faster recognition of gain, but also lessens the tax fees due to the high cost of performing the appropriate analysis for a non-475 fund.
A 130–30 fund or a ratio up to 150/50 is a type of collective investment vehicle, often a type of specialty mutual fund, but which allows the fund manager simultaneously to hold both long and short positions on different equities in the fund. Traditionally, mutual funds were long-only investments. 130–30 funds are a fast-growing segment of the financial industry; they should be available both as traditional mutual funds, and as exchange-traded funds (ETFs). While this type of investment has existed for a while in the hedge fund industry, its availability for retail investors is relatively new.
A 130–30 fund is considered a long-short equity fund, meaning it goes both long and short at the same time. The "130" portion stands for 130% exposure to its long portfolio and the "30" portion stands for 30% exposure to its short portfolio. The structure usually ranges from 120–20 up to 150–50 with 130–30 being the most popular and is limited to 150/50 because of Reg T limiting the short side to 50%.
In universal algebra and in model theory, a structure consists of a set along with a collection of finitary operations, and relations that are defined on it.
Universal algebra studies structures that generalize the algebraic structures such as groups, rings, fields and vector spaces. The term universal algebra is used for structures with no relation symbols.
Model theory has a different scope that encompasses more arbitrary theories, including foundational structures such as models of set theory. From the model-theoretic point of view, structures are the objects used to define the semantics of first-order logic. For a given theory in model theory, a structure is called a model, if it satisfies the defining axioms of that theory, although it is sometimes disambiguated as a semantic model when one discusses the notion in the more general setting of mathematical models. Logicians sometimes refer to structures as interpretations.
In database theory, structures with no functions are studied as models for relational databases, in the form of relational models.
In mathematics, progress often consists of recognising the same structure in different contexts - so that one method exploiting it has multiple applications. In fact this is a normal way of proceeding; in the absence of recognisable structure (which might be hidden) problems tend to fall into the combinatorics classification of matters requiring special arguments.
In category theory structure is discussed implicitly - as opposed to the explicit discussion typical with the many algebraic structures. Starting with a given class of algebraic structure, such as groups, one can build the category in which the objects are groups and the morphisms are group homomorphisms: that is, of structures on one type, and mappings respecting that structure. Starting with a category C given abstractly, the challenge is to infer what structure it is on the objects that the morphisms 'preserve'.
The term structure was much used in connection with the Bourbaki group's approach. There is even a definition. Structure must definitely include topological space as well as the standard abstract algebra notions. Structure in this sense is probably commensurate with the idea of concrete category that can be presented in a definite way - the topological case means that infinitary operations will be needed. Presentation of a category (analogously to presentation of a group) can in fact be approached in a number of ways, the category structure not being (quite) an algebraic structure in its own right.
The structure of a thing is how the parts of it relate to each other, how it is "assembled".
Structure may also refer to:
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