I am no big fish, but as someone who has an average price of under $300 per bitcoin, I don't really feel the urge to sell.
The recent rise has been slow and steady, I expect that if the price starts to fall, it will also move quite slowly.
I don't expect to be at a paper loss anytime soon, hopefully ever, so I am happy to sit and wait. I am not buying at the moment, but I am not selling either (gold parity might change my mind though)
Your break-even price is under $300 per coin, and you are still not going to sell your bitcoins. What about whales then who didn't buy their bitcoins at all but mined them in the early days of Bitcoin, when it was still possible to mine coins on an average desktop computer in the thousands? The cost of these coins is negligible, so any real price would mean huge returns for all these people.
I'm not an advocate of blindly holding regardless of price or life situation, but at the moment I don't need to sell. I am well into profit and I have had all of my coins for over 1 year so can sell tax free.
If I need some fiat, I will sell. I wouldn't sell for fiat if the price was $200. I won't buy now, but if it was $200 for BTC I would.
People sitting on huge piles of Bitcoin from mining years ago should be wealthy now. If they are living at home and from paycheck to paycheck so that they can hold their BTC, that is stupid.
I would assume that they have already done pretty well out of Bitcoin, are at least quite well off, own a house and car, have no debt, can vacation regularly etc.
Now they have no real need to sell, so hold in the hope of further appreciation.