That is a very bad news for the market. This news might affect the price of Bitcoin. I am amazed by the increasing number of attacks by hackers now day. It has become so common.

This can be an insider's job, if you look into the amount that was stolen.

Obviously reading something like this is a concern that can still happen again and the value is quite fantastic. is it just because of negligence? I don't feel that until there is definitely something else not yet known. hopefully it can be revealed.

It's hard to believe stories like this. It could have been staged by the owner to run away from obligations (i.e. taxes). Who would really store a huge amount on their mobile phone? And to say that he is a security expert makes it even worse. If it were true, did he really asked for the miners to rollback?

We are near on halving and this is a very sad one for the owner.
This might also affect the price since the hacker could dump it all.
But what if this was just stage? To create FUD and start the dump?

So, it turns out there are whales that don't bother to take basic measures to protect their own money. That much money should have been stored in a hardware wallet or airgapped computer not somewhere connected to the internet. There are a few hacking programs that make it easy for novices who know almost nothing about hacking to hack into things. I saw a port scanner a few weeks ago that performs different exploits depending on the protocol it finds and there's that Havij thing the hacker talked about in his Steemit post. There was even a computer virus called Zeus that was easy for anyone with little hacking knowledge to operate and it took several law enforcement agencies to shut down that network.

Moral of all this is to hide your money, because anybody with a little hacking knowledge can steal it.

A mutable blockchain is simply a ledger. A miner that would allow to reverse the transaction somehow, would risk being forked off the network, if not, he would be risking the value-proposition of what he's mining.

But I'll bet for the right people BCH and BSV would do it. All it would take is one phone call to the one miner.

Other than that what type of whale has any money riding on sim card? No matter who you are you should at least know that's not a great idea.

I don't see an "increasing number" of hacker attacks.Such attacks are a constant threat for the last 6 years and hackers are only getting better at finding weak spots in the security systems.This is a never ending battle.Perhaps the amount of hacker attacks goes up a little bit,because of the BTC bullish price trend,but this is not a significant amount(and there's no exact data about all hacker attacks that are reported).
However,how the hell can someone HODL such large amounts of BTC and BCH on one place?This is really stupid move.I agree that it's most likely an insider's job.

Losing that kind of btc and bch was the one who is getting dangerous and mind-blowing especially that he is also a big whale from China who is kind of manipulating the market sometimes. The thing is I don't know what would be the connect of the miners or what kind of help can the miners give to the big whale ho lose a lot of bch and btc? That was the question and why is he asking the help of it because if that's the case then probably crypto enthusiast will be the one to contact first to verify and check the security of it.

I feel for this person.... I was a victim of a SIM Hack on my online Banking and I lost a lot of money. It took years to pay back the money that the person stole <shifting money from my bond into the debit account and withdrawing that too> 

That was one of the reasons why I researched alternative payment options, because I realised that syndicates within the Bank was working with people from outside to steal people's money and there is nothing that you can do about it. The Banks NEVER accept responsibility for so-called hacks like this and they always put the blame on you.

Now, you take full responsibility for hacks... and you are in the same situation that you would have been, if your money was stolen in your Bank account. 

The miners are definitely not going to help this person... but I think the poor person is desperate ...so he or she is trying everything to get it back.