I don't think big holders (whales) let gonna crash bitcoins. They are the major party currently controls the bitcoin price.
Yep, people like them won't make Bitcoin go down since they really invested big enough. And just imagine that only few people know about Bitcoin. What if everyone will notice it? Just imagine.
Big whales really make bitcoin go down, for them to harvest bitcoin on the panic sellers, for them to earn big profit when the price of bitcoin increase. But the dropping of bitcoin does not mean its going to die. Bitcoin wont crash for now because bitcoin dont have competitor. I said now because as you can see, the technology now is upgrading fast, as the technology upgrades, many opportunity will come, so its possible that bitcoin will be bright or not, because someone might create bitcoin competitor.