Theoretically if there will be less sellers then prices will jump up high.
If you notice gaps in market, that means there is a strong trend is going on and people do cancel their orders.

If there is no seller in markets then buyers will go cray and will be ready to buy at whatever price strike on their mind which may convince someone and then may decide to sell on those crazy prices.

All today's buyers are tomorrow's sellers if there will be a convincing price available. So, theoretically all people may not stop selling.