New drug for depression fails phase II trial, Biohaven (BHVN.US) plunges nearly 13% pre-market! Why is Wall Street collectively "defending" it?

According to the Wisdom Financial app, despite Wall Street analysts defending Biohaven's announcement on Christmas Eve, the biotech company (BHVN.US) still fell nearly 13% in pre-market trading on Friday - after a Phase II clinical trial for its anti-depressant candidate BHV-7000 was declared a failure.