SBI Crypto shuts Bitcoin pool as three miners control 60% of network
In brief
- SBI Crypto shut down its Bitcoin pool in Japan on July 31 after significant hashrate loss
- Foundry USA, AntPool, and F2Pool held 60% of recent blocks at shutdown
- SBI's seven-day average hashrate dropped 64% in the month prior
- Destination of SBI's lost hashrate remains unclear in aggregate network data
The Shutdown Timeline
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 after that point. The company then scheduled a full Stratum shutdown by 23:59:59 UTC.
By the time the pool went offline, its operational presence had already evaporated. At 11:22 UTC on July 31, SBI Crypto was down to 0.72% of attributed blocks, a stunning collapse from where it stood weeks earlier.
The Hashrate Freefall
The decline wasn't sudden. SBI Crypto's 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 — a 64% loss in a single month. By 11:17 UTC on July 31, the 24-hour average hashrate was about 0.452 EH/s, signaling the pool was already running on fumes.
The pool's share of the network had been eroding for weeks. SBI Crypto's share fell from 0.9804% to 0.6192% between July 20 and July 27.
Concentration at the Top
The timing of SBI's exit coincided with a significant shift in mining concentration. Later that day, a Hashrate Index reading put Foundry USA, AntPool and F2Pool at 60% of recent blocks. The three pools weren't new to dominance — the top tier had cleared 60% before the cutoff.
At 11:22 UTC on July 31, the breakdown was clear: Foundry held 26.67% of attributed blocks, AntPool 17.13%, and F2Pool 16.21%.
A critical unknown remains: the routes behind SBI Crypto's lost pool hashrate stay hidden in these aggregate totals. Without detailed tracing, it's unclear whether SBI's former miners migrated to one of the three dominant pools, scattered across smaller operations, or shifted to solo mining.
