The volume in poloniex has been decreased too much, i remember when it was >11,000 ETH but now it is ~1600 ETH, are people collecting (holding) Ethereum to sell in future?
The volume was ~12K BTC at it's highest and now 1.6K BTC.
Some people hold, some trade and some bought to build Dapps.
Normal IMO
Today the volume of Etherium was increased again by more than 100%, so and the price was very unstable today. Yeah people are holding to sell after months or years.