"The Bid will be conducted between February 1, 2023 and January 31, 2024 through a combination of discretionary transactions and automatic repurchase plans..." (CN, 2023)
References:
CN. (2023, Jan 24th) CN Announces new Normal Course Issuer Bid for Share Repurchase and 8% Dividend Increase. Retrieved from CN: https://www.cn.ca/en/news/2023/01/cn-announces-new-normal-course-issuer-bid-for-share-repurchase-a/
Published on January 31, 2023