There is an interesting theory posted yesterday on reddit by TraderJoeSmo suggesting that EOS Foundation has been crashing the market recently. EOS has been transferring more than 1 million Ether from their crowd sale campaign wallet to Bitfinex exchange. In the last few days Ethereum is falling in price by 8-9%, more than the usual 4-5% per day in a bear market and on Bitfinex Ether was trading 30 dollars lower than the other exchanges, which means that someone was on a selling spree.
The dates that the funds were being transferred perfectly line up with the dates that the market was dumping. You can check all the outgoing transactions from EOS crowd sale wallet with this Etherscan link https://etherscan.io/txsinternal?zero=false&a=0xd0a6e6c54dbc68db5db3a091b171a77407ff7ccf&valid=true
At the time of writing in the crowd sale there are still around 245k Ethers so if this is true there still a few thousands to be sold. https://etherscan.io/address/0xd0a6e6c54dbc68db5db3a091b171a77407ff7ccf
There are a lot more examples of these really big amounts concentrated in the hands of few. The most prominent example is Mt Gox Bitcoin wallet. The infamous first crypto exchange that was hacked back in 2013 got court permission to start selling the remaining Bitcoin that is holding in order to repay people that lost their funds as the crypto exchange bankrupted. In January big movements were noticed from Mt Gox wallet to exchanges at around the same time that the correction was beginning.
We have to remember that Crypto is still a very small market and most probably we will see a few more of these incidents again in the future. It seems that Crypto Currencies, the first application of decentralization, are still pretty centralised.