The huge operation of the whale may affect the market, and the operation of the huge whale is also transparent in Bitcoin. We can check their actions at any time and analyze market trends.
Does the ground gets wet when it rains? As long as there are any markets in the world, there will be people trying to manipulate it, it doesn't even have to be a whale, it is simply just profitable to manipulate markets if you can which means that people will keep on manipulating it as long as they can. It is simple as that.
I personally never tried it but there were very small coins that people manipulated while I was there as well and I had to contribute to their manipulation once to get out, otherwise I would have to get out at low technically. All in all it is not really a smart decision to keep on hurting the market, because in the end you will end up with a hurt market and can't keep on manipulating to make a profit.