After 4:40 PM GMT (11:40 AM ET), on November 15th, the Bitcoin Cash (BCH) blockchain will undergo a hard fork and BitGo will be supporting the ABC chain, which is believed to be the dominant chain.
We recommend ceasing transaction activity in and out of all Bitcoin Cash wallets two hours prior to the fork, at approximately 2:40 PM GMT (9:40 AM ET) in order to ensure safekeeping of funds.
Understanding the Bitcoin Cash hard fork:
Twice a year, the Bitcoin Cash (BCH) blockchain undergoes a hard fork which integrates scheduled protocol upgrades. Most of the time, these hard fork upgrades go unnoticed and the BCH blockchain continues on.
This time was different; the community was not able to reach consensus on the direction of BCH and as a result, the BCH blockchain is expected to fork into two separate chains.
The two disagreeing groups are a coalition supporting a prospective chain called Bitcoin ABC (ABC), and a group led by NChain supporting a prospective chain called Bitcoin Satoshi’s Vision (SV). There is possibility for a third chain, in which some network participants continue with the pre-fork Bitcoin Cash rule set.
ABC fork introduces non-backwards compatible protocol upgrades including two new operation codes and canonical transaction ordering
SV fork will restore more legacy operation codes and increase the maximum block size
Strong early sentiment indicates that ABC will be the more valuable chain with greatest hash support. Believed to be the dominant chain, BitGo custody and wallets will support ABC.
We will determine after the hard fork if we want to add support for Bitcoin SV based on the BitGo Fork Policy at http://bitgo.com/info/forks.
How BitGo will handle the fork:
BitGo will shut down receiving and sending of transactions from Bitcoin Cash wallets for at least two hours starting at 4:40 PM GMT (11:40 AM ET). API users wanting to transact immediately after the hard fork will need to pass the ‘unsafeSplit’ flag on sending attempts to acknowledge the risk of their transactions being replayed to the Bitcoin SV chain. This requirement will be lifted when BitGo deems it safe. If disintermediation of funds will be required, it may remain in place until replay-protection is implemented.
Further details will be posted to our engineering blog.