 Shares of Athira Pharma Inc. apha plummeted 66.9 toward a record low in active afternoon trading Wednesday, enough to make them the biggest decliners trading on major market indexes, after the biopharmaceutical company said a Phase 2 study of its Alzheimers treatment failed to meet the primary endpoint. Trading volume spiked up to 18.1 million shares, compared with the full-day average over the past 30 days of about 246,500 shares. 