Bitcoin Forum

Bitcoin is gearing up for what could be the biggest (and least understood) change to its software to date.

Often called simply a "digital currency," bitcoin is best viewed as a protocol (a set of code) that delivers data (in this case bitcoins) in defined quantities (called blocks) that are then stored in a sequence (called a blockchain) on a distributed set of global computers. Bitcoin is decentralized – in that many people help make the network function, and in choosing to run its software, users all agree to abide by the same rules to keep it operational.

It's these qualities that make the proposed change particularly divisive.

Called Segwit2x, the plan calls for a very specific fork (or a change to bitcoin's rules), one that would make certain rules valid that weren't valid before. Specifically, Segwit2x would change the size of the blocks passed regularly around the network and stored in the blockchain from 1 MB to 2 MB.

Some users think this is a good idea, others don't.

But to begin, it's important to note how this fork differs from others. Coming on the heels of the bitcoin cash and bitcoin gold forks, bitcoin users might be accustomed to certain outcomes – ones that might not be guaranteed in the case of Segwit2x.

With bitcoin cash and bitcoin gold, for example, bitcoin users could have paid little to no attention and it wouldn't have impacted their transactions. If you held bitcoin on certain exchanges (or your own wallet), you received new cryptocurrency.

This smooth outcome, however, isn't guaranteed with Segwit2x. Complicating matters is that in many ways, Segwit2x sounds (and is) similar to other bitcoin forks.

Like other recent forks, Segwit2x is:

An alternative software – A modification of the bitcoin software run by network participants and that enforces the protocol rules. In this case, Segwit2x's code is called BTC1.
An attempt to increase the block size – Most forks focus on one specific rule of the network (block size), despite other possible optimizations that could lead to capacity boosts.
A hard fork – Anyone whose software is not upgraded to the new rules will no longer be a part of the network.
It's the differences, however, that stand out this time around.

First and foremost, whereas bitcoin cash developers appeared content to create a new blockchain (with new rules), Segwit2x's goal is to keep all bitcoin's existing users on one blockchain.

In this way, Segwit2x could have different outcomes.

These include:

Bitcoin's rules change. Most (or all) miners upgrade their software. The bitcoin blockchain continues to function but features larger blocks. Segwit2x's rules become the rules of bitcoin.
Two bitcoins are created. Only some miners upgrade their software. This creates two blockchains – a so-called "legacy" bitcoin, and a "Segwit2x" bitcoin, both with different rules and unique cryptocurrencies.
Bitcoin's rules do not change. No significant miners run the new software, and the network continues to run the current rules.

SegWit2x will not be a free money or an airdrop if it will fail from the begging for technical reasons, or if it will quickly overtake the real Bitcoin, or if most users won't have access to replay protections. If none of this will happen and if markets will be open, than after a process of claiming (which might be more complicated than claiming of BCH was) users will be able to get their free altcoin and dump it for somewhere between 0.05-0.15 BTC per coins, which is a nice 5-15% bump to their BTC portfolio. But since this fork is different from BCH, it's better to not make any hasty moves in order to not lose any coins due to replays or other disruptions.