Not necessarily insiders, institutions are the more likely scenario, hence no filings.
OBV tracks institutions/insiders buy/sells ... so when I see it drop off a cliff, tells me folks want out for a reason.
I cant tell you what to do because I have only recently begun having interest here, just never bought.
All I can recommend is that you watch this one closely.
The Above Message Likely Contains Coarse Language and, Due to its Content, Should Not Be Viewed By Anyone.