The High Yield Master II Index came into being in 1989. Martin Fridson, who then headed Merrill Lynch's head of high yield bond research department, brought a problem to the attention of Phil Galdi, who was responsible for bond indexes. The existing High Yield Master Index excluded two types of issues that were becoming popular because of the boom in leveraged buyout financing, zero-coupon bonds and payment-in-kind (PIK) bonds. Galdi's solution was to maintain the existing rules for the Master Index, but to create a new index that included "zeros" and PIKs. The new Master II was introduced with retroactive data that extended its history back to August 31, 1986.