GlaxoSmithKline (GSK) Gains But Lags Market: What You Should Know Posted byZacks Equity Research December 21, 2021 Leave a comment on GlaxoSmithKline (GSK) Gains But Lags Market: What You Should Know GlaxoSmithKline (GSK) closed the most recent trading day at $43.36, moving +0.7% from the previous trading session.