Pyramid

A polyhedron having a polygonal base and triangular sides with a common vertex

(stock market) a series of transactions in which the speculator increases his holdings by using the rising market value of those holdings as margin for further purchases

A massive monument with a square base and four triangular sides; begun by Cheops around 2700 BC as royal tombs in ancient Egypt

Use or deal in (as of stock or commercial transaction) in a pyramid deal

Arrange or build up as if on the base of a pyramid

Increase rapidly and progressively step by step on a broad base