Costco Wholesale Corporation Loss Form

(i) Costco lacked effective internal control over financial reporting; (ii) as a result of the foregoing, Defendants’ statements about Costco’s business, operations, and prospects, were false and misleading and/or lacked a reasonable basis.

On October 4, 2018, Costco announces that “in its upcoming fiscal 2018 Annual Report on Form 10-K, it expects to report a material weakness in internal control. The weakness relates to general information technology controls in the areas of user access and program change-management over certain information technology systems that support the Company’s financial reporting processes. The access issues relate to the extent of privileges afforded users authorized to access company systems.” Following this news, shares of Costco fell from a close of $231.68 on October 4, 2018, to a close of $218.82 the following day.