Bugs at the porchlight.
At the risk of coming across as Moses, greed is the denial of risk.
With shares being brand new, in the clearing process, I would imagine it takes time to hypothicate shares in order to be borrowed.
Given the type of brokerage the OP probably deals with, I doubt they would let him borrow (assuming ANY were available). Fiduciary responsibilty.
Fills amidst the initial volatility would interesting.
I watched a guy in 1998 short EBAY around 30ish. Met margin calls for awhile. Lost 6 figures on that one position. EBAY peaked at about 119 in 2005 pre-split.