You want my take? Thought I had posted it at least a dozen times already. My opinion is insiders and/or institutions weren't happy with the results from the testing and dumped shares. The CEO's letter to shareholders confirmed he has no answers.
I am bothered not by the share price drop (although I certainly wasn't happy about it), but instead, the order in which the actions occurred. "Someone" of consequence and size was selling before the info hit the streets.
I had posted weeks earlier that a flag formation in the charts can go either way, this one spiked down.
FWIW, it finished the week above the support line so that's a good thing. However, I am currently out of the stock.