Imagine yourself buying 1 egg for 10$ each.
Would you still buy more?
This is whats happening right now.
Whales have driven the market up, and along them, you & i & others have bought.. so they will start selling some of their bags, they will sell enough coins just to make it look as if a major drop is happening.
This will stir fear in the hearts of retailers (you) forcing you to either cut your profits or even sell at a loss.
This will also cause the price to drop more, so now the egg is not 10$ its 6 or 7$
This way they will buy and will repeat the process, making more money.
I know for sure, no whale will want to sell his holdings before the halving.