Yes, the naked short possibility is for sale of an overallotment. POET should be so lucky.  One could guess that Maxim was the passive market maker today, given the number of shares traded compared to the daily average.  That much volume could have put the stock price in the pennies without one.  Still, the prospectus is just preliminary, as far as the market knows.  It is not final.  It has no dates and it has no prices.  POET management needs to come clean as to what is going on here.  The stock may get halted until they give the market an explanation.  Then the CFO needs to resign.