MaxBTC.

MaxBTC was a Bitcoin mining poolMining poolA group of miners who share the work of finding blocks and split the rewards, so each gets paid steadily instead of rarely. run by Payward, Inc., the parent company of the Kraken exchange. Its pages carried the line “© 2011 Payward Inc.”, and by November 2013 maxbtc.com was sending visitors to Kraken’s site. A block found by MaxBTC doesn’t mean the transactions inside it went through Kraken.

It found its first block, 174,819, on 8 April 2012, and its busiest month was August 2012, with 73 blocks, about 1.5% of all blocks that month. In all mempool.space credits it with 449, about 0.05% of all Bitcoin blocks. It shared out rewards by the “double geometric method”, a scheme described by Meni Rosenfeld in 2011: each block’s reward went to the miners who had worked towards it, with older work counting for less after each block found. Its miners also mined Namecoin, a separate coin that can be mined with the same work. Each MaxBTC block’s first transaction paid the whole reward to one of the pool’s addresses, and the pool paid its miners from there. These are payments to the pool’s miners, separate from the transactions confirmed inside the block.

In March 2013 its site showed 36 miners. Its last block, 245,391, came on 8 July 2013, and a notice on its site said: “We regret that the pool will close indefinitely on August 3rd at 12PM PDT. All balances not withdrawn will be sent to addresses registered with us.” It gave no reason.