Bitcoin pool GHash.io announced on Wednesday that “it is not aiming to overcome 39.99 [percent] of the overall Bitcoin hashrate."
This marks a clear departure from the large pool’s recent flirtations with 51 percent. If that threshold is crossed for sustained periods of time, it concentrates power in ways that Bitcoin’s decentralized design normally does not allow.
“If GHash.io approaches the respective border, it will be actively asking miners to take their hardware away from GHash.io and mine on other pools,” the statement continues. “GHash.io will encourage other mining pools to write similar voluntary statements from their sides.”