Just to add a little more. From the POS Am filed 2 days ago, I extracted these 2 statements (both on page 12).
The sale of the shares may be effected in one or more of the following methods:
Ordinary brokerage transactions and transactions in which the broker-dealer solicits purchasers, which may include long or short sales.
In addition, the selling stockholder may enter into hedging transactions with brokers or dealers who may engage in short sales of shares in the course of hedging the positions they assume with the selling stockholder.
Finally here's more pertinent data from the S-2 filed today:
(Page 18) The selling stockholders may sell their shares by one or more of, or a combination of, the following methods:
settlement of short sales entered into after the date of this prospectus.
(page 19)
In connection with the sale of the common stock or interests therein, the selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of the common stock in the course of hedging the positions they assume. The selling stockholders may also sell shares of the common stock short and deliver these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that in turn may sell these securities.