three-year period determined by reference to the ownership of persons holding five percent ( 5% ( 5 % ) ) or more of that company 2019s equity securities . if a company undergoes an ownership change as defined by i.r.c . section 382 , the company 2019s ability to utilize its pre-change nol carryforwards to offset post-change income may be limited . the company believes that the limitation imposed by i.r.c