If I were holding a large amount of Bitcoins worth millions of dollars, I would start cashing out right now before it's too late.
Think about it deeply, either split happens and value halves in less than half of the current value or everything will go smooth.
But if split happens then imagine that your coins will be priced 50% less for almost 2-3 years before the market gains the trust and starts growing again.
Are you willing to put millions of dollars on hold for 2-3 years?
Is this really what everyone expects to happen, a 50% drop?
What is the effect on ETH LTC? Same ?
you shouldn't even begin to compare ethereum split with bitcoin's possible split.
ethereum is centralized and they have millions of coins at their disposal (some speculate about 70 million) and when the split happened they started dumping coins on ETC market to prevent its price to go up and then used the funds to put up buy walls to prevent ETH crash.
there is no such thing in bitcoin!