It's legit, but it's hard to know whether they were bought or sold. Ruling out a naked position, word on the street is that they are part of a bear call spread.
Quote from increasenow:
ah, but you do not know if they were buying the 10,000 (hoping SPY rises) or writing the option (hoping SPY tanks)...SO, bottomline, one does no thave a clue if the 10,000 represents a bearish or bullish sentiment...sorry, wish it was this easy