For purposes of this section— (1) In general Except as otherwise provided in this subsection, the value of the old loss corporation is the value of the stock of such corporation (including any stock described in section 1504 (a)
(4)) immediately before the ownership change.
(2) Special rule in the case of redemption or other corporate contraction
If a redemption or other corporate contraction occurs in connection with an ownership change, the value under paragraph (1) shall be determined after taking such redemption or other corporate contraction into account.