the given scenario can be avoided if the person is knowledgeable about his stuff. It would be a dumb move if we keep on holding when we saw that Bitcoin is failing and the new cryptocurrency is emerging.
It's an even dumber move to fall for the fork, suddenly panic-sell all your Bitcoins because of FUD, and hand the fork-guys exactly what they want: your money!
A fork is no "new technology"!
This is why despite the fact I do not believe in bitcoin cash at all I still keep holding it, just in case they are able to get their goals of replacing bitcoin, I know that the odds of that happening are very low but I’m not going to take any risk, it was difficult to not sell by BCH with the huge prices it reached in the past days but I prefer to have an insurance that I’m not going to lose money in the future.
This way FOMO can make it an self-fulfilling prophecy to overtake a leading coin.
Never seen such a drastic increase in the value of bitcoin.
Obviously, absolute price increases get bigger when the price goes up, but you have to look at relative increases to put it in perspective. Take a look at
https://bitcoinaverage.com/en/bitcoin-price/btc-to-usd, select All-time, and select Log-view. You'll see Bitcoin went up much faster several times in the past.