Pure Storage (PSTG -11.90%) stock is falling in Thursday's trading following the company's recent fourth-quarter report. The company's share price was down 10.9% as of 2:30 p.m. ET.Pure Storage published its Q4 results after the market closed yesterday and actually posted results that came in better than Wall Street had anticipated. But the company's margins showed signs of weakening, and management's forward guidance disappointed the market.Pure Storage stock slumps as Q4 margins disappointPure Storage rep ...