It means that between December 15 & December 30, someone shorted 20k more shares of PHAR.
Anyone could have done it, we would never know who it was.
It could be an institution that someone works for.
It could be a hedge fund.
It could be a group.
Or...it could be a negative poster on the board.
The interesting thing is that all over IHub, you will hear that penny stocks CAN NOT BE SHORTED, yet over a half million shares of PHAR have been shorted since the middle of June last year. These ARE NOT the REG SHO list daily numbers, either.
All The Best