The stock is now trading at levels last seen in 1998.Share prices of Walgreens Boots Alliance (WBA -0.78%) plunged following the June 27 release of its fiscal third-quarter earnings report, with the stock having one of its worst days on record. The stock price has now fallen more than 53% since the start of 2024.Let's look at Walgreens' most recent quarterly report, why the stock plummeted, and whether now is the time to buy.Reduced guidance, store closures, and new planFor its fiscal Q3 (ended in May), Wal ...