Anyone can create a chain fork of Bitcoin at any time. The possibility of a SegWit2x hardfork (B2X) in November 2017 requires that we, once again, clarify our position on any and all potential hardforks.

BitMEX Hardfork Policies

At BitMEX, our top priority is protecting the assets of our customers. In order for us to effectively do this, we insist that any Bitcoin hardfork includes the following:

Strong two way transaction replay protection, enabled by default, such that transactions on each chain are invalid on the other chain.

A clean break, such that the new chain cannot be “wiped out” by the original chain.

A modification to the block header, such that all wallets (including light clients) are required to upgrade to follow the hardforked chain.

A change in address format, to prevent people inadvertently sending coins to an address on the wrong chain.

New P2P network magic, to ensure a functioning and reliable node network for both coins.

Strong replay protection and wipeout protection, in particular, are considered absolutely crucial. Should a hardfork not follow these policies, we will not support the new coin. To be clear, we do not intend to access or keep these coins. The administrative overhead of distributing any and all hardforked coins (including Bitcoin-based distributions like Byteball/Lumens) is prohibitive and BitMEX will not monitor or maintain balances of hard-forked coins.

Additionally, support of any forked currency is solely at the discretion of BitMEX. While we may snap users’ margin balances at the time of the fork in case we decide to distribute, there is no guarantee that it will be safe, desirable, or practical to do so. If this concerns you, you should withdraw your funds before any given fork and handle the split on your own.

SegWit2x (B2X) – BitMEX Policy

The SegWit2x (B2X) proposal is aimed at increasing the blocksize. It is scheduled to take place in November 2017. This change is incompatible with the current Bitcoin ruleset and therefore a new coin may be created.

Proponents of this new coin hope it becomes known as Bitcoin, however which coin is known as Bitcoin is not up to the proponents of the new token. Investors and traders may decide which coin has the highest value. In order for this process to work smoothly, strong two way transaction replay protection is necessary.

It is our understanding that the SegWit2x proposal does not include two way transaction replay protection, enabled by default. Therefore BitMEX will not be able to support SegWit2x.

As such, BitMEX will not support the distribution of B2X, nor will BitMEX be liable for any B2X sent to us. This policy applies even if the SegWit2x chain has the majority hashrate. Therefore, it is up to our users to withdraw their Bitcoin’s from BitMEX prior to the fork if they wish to access B2X.

BitMEX considers any and all contentious hardfork tokens as altcoins. The .BXBT and .BXBTJPY indices will remain unchanged and will not include B2X.