Really? Who sells 2K coins at market at once like that? The only purpose of that is to try and push the price down.
Bitpay...You can watch the traffic through the BitPay wallet on this website:
http://www.walletexplorer.com/wallet/BitPay.com?page=30
That wallets continuously receives ~1000 small inputs every day, and now and then sends out batches of a dozen small outputs. (Could these be merchants who want to get some bitcoin? Or customer refunds?). Once in a while, when the wallet's balance has grown enough, BitPay sends a large round amount elsewhere, often to Bitstamp. Here is one such transaction:
2014-12-18 13:11:07
http://www.walletexplorer.com/txid/ed981090f3efc585036ba2206335799640baaa6b4ac1846a3189731549649018
Sent 2000 BTC (exact) to Bitstamp's input wallet
Sent a crumb of ~0.1 BTC to some other address (probably a new address in Bitpay's wallet, not yet identified as such).