Ethereum sales finally wrap up tomorrow.
The drop will stop as soon as people sending them bitcoin.
I would guess the ethereum sale likely drove the price up on bitcoin over the past few weeks. To date they have pulled in 31,528 coins and only sold something like 3,737. As they unload the remaining 27,791 coins THAT will put steady down pressure on the price. I would guess they would feather it in over time but I wouldn't rule out some hard dumps.
Ethereum wallet
https://blockchain.info/address/36PrZ1KHYMpqSyAQXSG8VwbUiq2EogxLo2
