Cryptocurrency mining pool F2Pool has stopped signaling support for SegWit2x, potentially undermining the argument for the November implementation of the controversial scaling proposal.

In May, F2Pool joined virtually every significant mining operation in signing the New York Agreement, the Barry Silbert-led proposal that sought to solidify consensus for SegWit2x, a protocol upgrade that supporters say will help the Bitcoin network scale to manage larger volumes of transactions more efficiently.

However, a significant portion of the bitcoin community — including Bitcoin Core developers — oppose the SegWit2x hard fork, which has led to an increasingly-contentious debate within the ecosystem, making it appear likely that the Bitcoin network will split into two different, competing blockchains in mid-November.

Although SegWit2x maintains strong support from major industry players like Coinbase, BitPay, and Xapo, a litany of smaller companies have withdrawn their signatures from the New York Agreement as SegWit2x’s scheduled November implementation has gotten closer. However, SegWit2x supporters continued to point to the fact that roughly 95% of the mining hashrate was signaling approval for the hard fork.

That changed on Thursday when mining pool F2Pool officially stopped signaling for SegWit2x. This was not a surprise. Though F2Pool had signed the New York Agreement, they stipulated that their support only carried through until July; if the hard fork had not been implemented by then, they would no longer support the proposal.

Nevertheless, the pool continued to signal for SegWit2x during the intervening months, stating that they would remove their support the next time they upgraded their pool servers. Meanwhile, SegWit2x proponents continued to include F2Pool’s hashrate in their assertion that the hard fork had support from 95% of the total mining power.

Now, F2Pool — which accounts for about 10% of the Bitcoin hashrate — is no longer signaling for SegWit2x. “15% down, 85% to go,” BitGo engineer and SegWit2x critic Jameson Lopp tweeted.

ViaBTC, meanwhile, has stated that it will allow its pool users to mine whichever blockchain they want, making it difficult to ascertain how much of that pool’s hashrate will commit to the new blockchain.

Noting these developments, some analysts theorize that traders and investors are skeptical that SegWit2x will execute the hard fork next month, leading to the present rally that has lifted the bitcoin price to a new all-time high above $5,200.

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