I am lost as to this quiet period.  How do we kno

I am lost as to this quiet period.  How do we know what event caused it?  Any guidance as to what it was about, why it being over is so positive, etc. would be helpful.

I am aware of what a quiet period is and for them to have been in one usually involves some sort of development, but would just signing up a clinical center to run a trial qualify for that?