On January 2, 20X5, Ancud Corporation bought 10 percent of Castro Corporation's capital stock for $90,000. Castro's net income for the year ended December 31, was $130,000. During 20X5, Castro declared a dividend of $30,000. On December 31, 20X5, the fair value of the Castro stock owned by Ancud had increased to $99,000. How much should Ancud show on its 20X5 income statement as an unrealized holding gain?