often we see some short covering early in the morning, and then price drops back after it settles down. Vol seemed to be too low on the early move up to indicate anything other than short covering, though anything is possible. Could have been a buyer wanting in before open.
why would a short take chances on covering the open... most shorts I know cover midday... mornings can spike up on overnight news... very dangerous for a short. Long term can usually SELL opens and get the best price of the day on most stocks. Brokers have BUY AT OPEN buttons and limit orders.. therefore that is the time of most up spikes. Sell at close is done by traders... they give up and don't want to be in overnight.