" Who is selling at this volume and why?"
Painfully obvious the bulk of selling is from the self serving ERBB CD insiders steadily profiting 50%+ gains!
You can monthly track ERBB share structure details..confirms O/S increases, restricted, unrestricted shares..
Per otcmarkets as of 5/31/20:
O/S .............692,428,496
Restricted ....1,696,223
Unrestricted ... 690,732,273
ERBB CD team daily dilution pressure continues pushing accumulators into downward price trend..Odds ain't fair for everyday erbb shareholder..Infrequently, a bone is tossed with an "embellished" paid PR for short term spike opportunity..:) ..gltu