By the time SBI Crypto pulled the plug on its Bitcoin pool in Japan on July 31, its seven-day average hashrate had fallen 64% in a month. Later that day, a Hashrate Index reading put Foundry USA, AntPool and F2Pool at 60% of recent blocks. The timing makes them look connected. Weekly data tell a messier story.

SBI Crypto’s official update set the first cutoff at 22:00 UTC on July 30, or 07:00 JST on July 31. Share acceptance stopped, and miners began a graceful disconnect. The company scheduled a full Stratum shutdown by 23:59:59 UTC. Its website would stay open for historical data and payout status. The final payout schedule remained unspecified, as did the end dates for API and portal access.

At about 11:22 UTC on July 31, Foundry held 26.67% of attributed blocks, AntPool 17.13% and F2Pool 16.21%. SBI Crypto was down to 0.72%, or an estimated 6.8 exahashes per second. The dashboard moved again within minutes. The 60.01% reading captures a moment, rather than a lasting level of control.

SBI Crypto’s daily telemetry charted a month-long retreat. Its seven-day average BTC hashrate dropped from 16.222 EH/s for the period ending June 30 to 5.817 EH/s for the period ending July 30. By 11:17 UTC on July 31, separate operational statistics put the 24-hour average at about 0.452 EH/s. SBI’s official block list showed July 29 as its latest block.

The top three were already above 60%

Matched weekly buckets from mempool.space put Foundry, AntPool and F2Pool at a combined 64.8039% for July 20, then 60.7843% in the still-incomplete July 27 bucket. SBI Crypto’s share fell from 0.9804% to 0.6192%. The top tier had cleared 60% before the cutoff. The July 27 bucket spans the shutdown and remains incomplete, leaving any immediate concentration effect unmeasured.