The top reason to drop right now would be traders selling out on a break of trend. There are a lot traders just front running the next 'scheduled 9 month bubble' which might not happen.
A much simpler explanation is that hedge funds or other funds that are interested in buying into the auction are employing traders to push the price down so they could bid lower.
They do it all the time on a regular stock market (push down before buying
en masse). That was described brilliantly by Jesse Livermore, who was always testing the downside of the market before buying a larger block. Read "Reminiscences of a stock operator"-a classic.