If one looks at todays Volumes and size of each Trade, this certainly does not appear to be a large Investor Unloading or Institutional lightening.
Rather it appears to me (as a personal assessment only)-- to be; "very short term weak hands"; panicking; or people/Traders; who bought on the recent GXY PRS positive News, expected their 10% quickie profit or whatever; did not get accomodated immediately to their satisfaction, and thus immediately unloaded; either to cover their own short money or for wahtever else their motives are/were.
Also the market 'thrashed' literally Everything today anyway!!