In one aspect the invention comprises systems and methods for providing hedging against loss of value of a block of variable annuity policies to be sold, between the signing and closing dates of the transaction. In one embodiment, a purchase price adjustment grid (or formula) is used to adjust the purchase price for the sale of variable annuities between signing and closing dates as a result of changes in market parameters over that time period. One aspect comprising the steps of: (a) storing data representing at least one equity amount table having a horizontal axis corresponding to a first variable and a vertical axis corresponding to a second variable; (b) receiving a first value of the first variable and a second value of the second variable; and (c) calculating a table amount based on a bilinear interpolation of quantities in the equity amount table.