Disclaimer: This article has been updated to reflect that BTC.Top has begun signaling for Taproot activation.

The top-10 Bitcoin (BTC) mining pools by hash rate distribution are now signaling for Taproot activation with BTC.Top being the latest among them as of the time of writing.

Indeed, 90% of Bitcoin’s hash rate briefly signaled for the protocol upgrade with the figure now standing at about 73%.

Tweeting on Monday, crypto exchange giant Binance announced that Binance Pool had begun signaling for Taproot. According to the Taproot Signal Twitter bot, Binance Pool’s maiden Taproot signal occurred at block height 683,878.

As previously reported by Cointelegraph, the two largest Bitcoin mining pools — AntPool and F2Pool — were among the earliest supporters of the protocol upgrade in the mining arena. SlushPool — the 12th-largest pool by hash rate distribution — was the first to mine the first transaction block with a Taproot signal.

BTC.Top, the last of the top-10 pools to signal for Taproot, did so on block height 683,945. The mining pool had previously announced that it had completed the testing protocols necessary to begin including Taproot activation signals in mined transaction blocks.

Data from Taproot.watch, a webpage created by Bitcoin developer Hampus Sjöberg, shows there have been multiple occasions of at least 10 successive blocks with Taproot signals during the current difficulty epoch.

Source: Taproot.watch

However, with 190 non-signaling blocks so far, Taproot activation being locked in during this current difficulty window appears unlikely. The protocol upgrade can only move forward if 90% out of the 2,016 mined blocks in a difficulty epoch include an activation signal.

At 190 blocks, the non-signaling blocks are now over 9%. At 202 non-signaling blocks, the Taproot lock-in threshold requirement will be pushed to the next difficulty adjustment in about 11 days.

Taproot activation must be locked in before Aug. 11 for the network upgrade to happen in November. If that happens, it will arguably be the most notable protocol-level improvement in the last four years for the largest crypto by market capitalization.

The Taproot upgrade will essentially mask spending conditions prescribed by transacting parties, a feature touted to have significant implications for both privacy and smart contract capabilities of the Bitcoin protocol.