This directory contains ontologies belonging to the Market Data (MD) domain. This domain contains ontologies that represent temporally variant concepts for the whole range of financial instruments, loans, and funds. While all concepts can be regarded as having some relationship to time, the ones in this domain are those concepts that explicitly have a set of past values a present value and projected future values. As such, this domain covers the concepts represented in market data, such as prices, yields, and analytics for debt and for pools of assets.