You would get a clearer answer if you specify the amount of bitcoin which are going to be sold. "Huge" can be anywhere from 1000BTC to 1MBTC. The former won't even move the market while the latter will likely result in a substantial drop on the price.
This is most dangerous for bitcoin as because of such panic sellings they lose their value up to very great extend which is very shameful fir such a worthy currency like bitcoin . It can only be protected by not allowing any panic news let into the market which might cause disturbance in the trust of holders