{tag=Coinbase transaction}
{title2=2022-10-20}
{title2=malformed Coinbase}

= Coinbase transaction of block 759475
{synonym}
{title2}

In this malformed <Coinbase> transaction, the mining pool "nicehash" produced a <provably unspendable Bitcoin output script> due to a bug, and therefore lost most of the entire <block reward> of 6.25 <BTC> then worth about \$ 123,000.

The output is unspendable because it ends in a constant 0, the disassembly of the first and main output is this series of constants:
``
0 017fed86bba5f31f955f8b316c7fb9bd45cb6cbc 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
``
and for the second smaller one:
``
aa21a9ed62ec16bf1a388c7884e9778ddb0e26c0bf982dada47aaa5952347c0993da 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
``
the third one being an <OP_RETURN> message.

This event received some coverage:
* https://twitter.com/hashrateindex/status/1583146537538170880
* https://www.linkedin.com/posts/david-westrop_block-759475-was-mined-without-a-payout-activity-6989026297020628992-qtx4/?originalSubdomain=lk

https://www.blockchain.com/explorer/transactions/btc/5660d06bd69326c18ec63127b37fb3b32ea763c3846b3334c51beb6a800c57d3


5660d06bd69326c18ec63127b37fb3b32ea763c3846b3334c51beb6a800c57d3

ID: 5660d06bd69326c18ec63127b37fb3b32ea763c3846b3334c51beb6a800c57d3