2017 has been the year of Bitcoin forks. For clarity’s sake, here’s a quick rundown: 1.Prior to August 1, 2017, miners activated the backward-compatible SegWit soft fork. This upgrade to the Bitcoin protocol increased the transactional capacity of blocks, fixed a serious bug known as transaction malleability, and paved the way for Lightning Networks and further improvements. 2. On August 1, the backward-incompatible Bitcoin Cash hard fork occurred. Bcash split from the main Bitcoin blockchain to create an altcoin with 8-megabyte blocks and no SegWit implementation. All Bitcoin balances held at fork time were credited an equal amount of Bcash (BCH). See our Bitcoin Cash article for more details. 3. On October 24, the backward-incompatible Bitcoin Gold hard fork occurred. Bitcoin Gold hard forked away from the main Bitcoin blockchain to create an altcoin with an altered, ASIC-resistant mining algorithm known as Equihash. All Bitcoin balances held at fork time will be credited with an equal amount of Bgold (BTG) when the Bgold network launches (presumably in the near future). See our Bitcoin Gold article for more details. 4. The SegWit2x (also known as S2X/B2X) backward-incompatible hard fork is scheduled to occur around November 16. B2X will fork from the Bitcoin blockchain to produce an altcoin with 2-megabyte blocks and SegWit support. All Bitcoin balances held at fork time will be credited with an equal amount of B2X. See our article on the New York Agreement (which set the stage for SegWit2x) for more details.
SegWit2x Details Breakdown
When?
The SegWit2x fork is scheduled for Bitcoin block 494,784, which will be mined sometime around November 16, 2017. For an updated projection of the date and exact time of the mining of block 494,784, visit the 2x Countdown page.
Why?
From a Bitcoiner’s perspective, SegWit2x is an attack by big miners and corporate interests, and it’s intended to seize control of Bitcoin development. It’s perceived as an attack primarily due to its lack of consensus and replay protection, which will almost certainly lead to chaos, confusion, and losses. Statements from the S2X team clearly indicate that S2X is intended to replace the existing Bitcoin.
Who?
Reddit-user readish compiled the following list of individuals known to support S2X publicly:
Development
Bitcoin Core and other key developers who’ve stated their opinions about SegWit2x are listed here (all are unanimously against it). Former Core dev and Bloq CEO Jeff Garzik is the sole SegWit2x developer. Garzik has been criticized for simultaneously working on yet another ICO altcoin called Metronome. “Today, Bitcoin faces existential threats from forks, developer drama, and so on.”
– Jeff Garzik on Metronome’s motivation There’s an obvious conflict of interest inherent in developing a contentious hard fork while also developing an ICO predicated on limiting disruption from such forks. The Bitcoin community’s reaction to this news was overwhelmingly negative and was summarized best by Samson Mow’s outraged tweet:
Code
SegWit2x was cloned from Bitcoin Core 0.14. Although Core’s latest version, 0.15, has been patched against a node-crashing exploit (disclosed by Chris Jeffry at the Breaking Bitcoin conference [2:29]), the SegWit2x client (known as btc1) remains vulnerable.
Odds of Success
To anyone following the developments, it’s clear that SegWit2x enjoys little organic support. What it does have is a high degree of miner signaling: 83% of blocks currently signal their miners’ support for the NYA. Stats from Coin.Dance. However, bear in mind that signaling is fairly irrelevant in this context. Signaling for Emergent Consensus (also known as the Bitcoin Unlimited fork, which failed to launch) reached 45% without effect. Adding a signal to each block mined costs miners nothing (and may even earn them extra money, if S2X supporters are willing to pay), so it shouldn’t be considered a reliable indicator. What ultimately matters is which chain miners will mine; all indicators point to this being the chain with the most value (the majority of users and economic activity). This is highly unlikely to be the S2X side. Markets are currently pricing B2X futures between 15% and 25% of BTC: Read more: Who Supports SegWit2x (Wallets, Exchanges): A Complete List | 99Bitcoins