A Fork in the Road- What to expect on the day of the fork

Exchanges, miners, developers, users and ethereum’s entire ecosystem is getting ready for a historical and defining hardfork. What does this mean for you and how will things go down on the day of the fork.

I’ve even written a cross-client network simulator to do some full fledged fork emulation and see if the network behaves properly… Results? Geth behaves correctly.
Péter Szilágyi, Software Developer at Ethereum Foundation

This post is meant to update users, miners and traders associated with the Ethereum on what to expect on the quick approaching hard fork.
The MainNet block on which the hard fork will occur is set at 1920000, which should be reached on Wednesday July 20 (this is only an estimate however).

Exchanges are ready with the required updates for the fork. Users will experience a block in deposit and withdrawal activity 1 Hour before the hardfork activities. All ETH on exchanges after the fork will be tokens of the winning chain (i.e. the chain with the most work on it). ETH deposits and withdrawals will be enabled again once the winning chain has become clearly evident.

Miners mining on pools should face no issues as the pools will update to the latest ethereum release automatically. Solo miners will have to manually update to the latest version of geth so as to stay up to date with the fork. Not updating would mean miners would effectively be mining "old" ether which would hold no value should the hard fork be implemented successfully.

Traders will be looking at volumes and volatility during the day. Much of the upward price movement has already been factored in to the price already, but there may be lots of room on the downside if the hard fork doesn't go off smoothly.

A hard fork on the ethereum network was last carried out during the update to Homestead.

For those of you who still aren't clear about what a hard fork is, a simple analogy would be that of a software update, a soft fork is essentially a backward compatible update that if you do chose to update gives you access to new features. For example an upgrade from Microsoft Office 2013 to Office 2016. Users can still access files on Office 2013 even if they don't update to 2016, despite being created on the new version.
A hard fork on the other hand is a mandatory update that if you don't perform will not only prevent access to new features but essentially wont be of use anymore. Microsoft withdrawing support for Windows XP would be an example of this, you could still be using XP but it won't be supported by developers and wont have security updates and patches available for it anymore.

I hope this helps clear things up and gives you an idea about what is going to happen during the upcoming hard fork.