Walgreens on Thursday announced plans to close a "significant" number of underperforming stores across the U.S. due to ongoing challenges with profitability and declining margins. The store closures are part of the company's multi-year footprint optimization program. While Walgreens didn't specify how many of its more than 8,700 stores will be affected, CEO Tim Wentworth told The Wall Street Journal that a "meaningful percent" of the underperforming locations would shutter. Walgreens shares tumbled in pre-m ...