When the price of the bitcoin will fluctuate more and more then me and my friends ( who are trader ) stopped Thier buying and selling work because they can't handle the condition of bitcoin price change and loss ( since chances of Profit are also Thier ) .
But if you will ask about the altcoin trading then surely with the increase of the price and decrease of the price the trading going on continuously Because the demand of the particular coin only depends upon the demand at the trading exchage which is regardless of the fact of the price of the BTC increase and down.
But I think only 1-2% chances are to be affected by the price down on the altcoins trading .