MEV 已以比以太坊更微妙的形式传播到比特币

有多种方法可以提前运行待处理的比特币交易。特别是其中一个可能会导致私人内存池，从而导致权力的集中化

MEV, or Maximal Extractable Value, has become a hot topic in the cryptocurrency world. It refers to the ability of those who verify transactions on a blockchain to choose the order in which they are processed, allowing them to extract value from the transactions themselves. While MEV has been a common occurrence on Ethereum, it has largely been absent from Bitcoin—until now.

MEV，即最大可提取价值，已成为加密货币世界的热门话题。它指的是那些在区块链上验证交易的人能够选择交易处理顺序的能力，从而使他们能够从交易本身中提取价值。虽然 MEV 在以太坊上很常见，但直到现在，它在比特币中基本上还没有出现。

In this article, we will explore the different ways in which MEV can manifest on Bitcoin, ranging from front-running NFT trades on marketplaces to the mining of empty blocks and the use of out-of-band payments. We will also touch on the potential implications of these practices, such as the slippery slope towards private mempools and the centralization of authority on the blockchain.

在本文中，我们将探讨 MEV 在比特币上体现的不同方式，从市场上的抢先交易 NFT 交易到空块的挖掘和带外支付的使用。我们还将讨论这些做法的潜在影响，例如私人内存池的滑坡和区块链上的权力集中。

MEV on Ethereum: A quick refresher

以太坊上的 MEV：快速回顾

As a quick refresher, MEV on Ethereum is possible due to the way transactions are processed on the network. When a user submits a transaction, it is placed in a mempool, which is a collection of pending transactions waiting to be included in a block and processed by a validator. The validators, who are selected based on their stake in the network, then choose which transactions to include in each block.

快速回顾一下，由于网络上处理交易的方式，以太坊上的 MEV 是可能的。当用户提交交易时，它会被放置在内存池中，内存池是等待包含在块中并由验证器处理的待处理交易的集合。根据他们在网络中的权益选择的验证者然后选择要包含在每个区块中的交易。

Since the validators are able to see all of the transactions in the mempool, they can front-run them by submitting their own transactions first. This allows them to extract value from the original transactions, such as by purchasing an NFT at a lower price before the intended buyer's transaction is processed.

由于验证者能够看到内存池中的所有交易，因此他们可以通过首先提交自己的交易来预先运行它们。这使他们能够从原始交易中提取价值，例如在处理预期买家的交易之前以较低的价格购买 NFT。

While front-running is one of the most common types of MEV on Ethereum, there are a number of other ways in which validators can extract value from transactions. These include sandwich trades, where a validator places two transactions around the original transaction to extract value from both sides, and transaction reordering, where a validator changes the order of transactions in a block to benefit themselves.

虽然抢先交易是以太坊上最常见的 MEV 类型之一，但验证器还可以通过许多其他方式从交易中提取价值。其中包括三明治交易，其中验证者在原始交易周围放置两笔交易以从双方提取价值，以及交易重新排序，其中验证者改变区块中的交易顺序以使自己受益。

MEV on Bitcoin: More subtle, but still present

比特币上的 MEV：更微妙，但仍然存在

In contrast to Ethereum, where MEV is a highly visible and well-defined phenomenon, MEV on Bitcoin is more subtle and can manifest in a variety of ways. Some of the most common include:

与以太坊相比，MEV 是一种高度可见且定义明确的现象，而比特币上的 MEV 则更加微妙，可以通过多种方式体现。一些最常见的包括：

Front-running NFT trades on marketplaces: One way in which MEV can occur on Bitcoin is through the front-running of NFT trades on marketplaces such as Magic Eden. When a seller lists an NFT for sale on these marketplaces, they create a Partially Signed Bitcoin Transaction (PSBT). The buyer then completes the transaction by adding their signature and paying the fee.

市场上抢先交易的 NFT 交易：MEV 在比特币上发生的一种方式是通过在 Magic Eden 等市场上抢先交易的 NFT 交易。当卖家在这些市场上出售 NFT 时，他们会创建部分签名的比特币交易（PSBT）。然后，买方通过添加签名并支付费用来完成交易。

However, if an NFT trader sees the transaction in the mempool, they can snipe it by broadcasting their own transaction that replaces the original buyer's payment and address with their own. To do so, they broadcast a Replace-By-Fee (RBF) transaction with a higher fee to ensure that their transaction is confirmed before the original one.

然而，如果 NFT 交易者在内存池中看到该交易，他们可以通过广播自己的交易来狙击它，该交易用自己的交易替换了原始买家的付款和地址。为此，他们广播了费用更高的替换费用（RBF）交易，以确保他们的交易在原始交易之前得到确认。

This allows them to purchase the NFT at the price set by the seller, while the original buyer is left out in the cold.

这使得他们能够按照卖家设定的价格购买 NFT，而原始买家则被冷落。

Mining of empty blocks: Another way in which MEV can manifest on Bitcoin is through the mining of empty blocks. Periodically, a bitcoin block is mined with nothing in it. The block is useless to anyone save the miner who won the block, as no transactions which are waiting to be confirmed are verified except for the coinbase (small "c," not the company) transaction which rewards the miner with the block reward.

空块挖掘：MEV 在比特币上体现的另一种方式是通过空块挖掘。比特币区块会定期被开采，但里面什么也没有。除了赢得该区块的矿工之外，该区块对于任何人来说都是无用的，因为除了用区块奖励奖励矿工的 coinbase（小“c”，不是公司）交易之外，没有任何等待确认的交易得到验证。

There’s a technical reason this happens, and really it’s an accident that empty blocks even occur, but it’s hard to argue that this is a) not MEV and b) good for Bitcoin (although it is also hard to argue that it’s bad).

发生这种情况有一个技术原因，事实上，甚至出现空块也是一个意外，但很难说这是 a) 不是 MEV，b) 对比特币有利（尽管也很难说这是坏事）。

Cartel behavior among miners: As we all know, Bitcoin is mined by powerful computers that solve complex mathematical puzzles. The miner who solves the puzzle first gets to add the next batch of transactions to the blockchain and collect the associated fees.

矿工之间的卡特尔行为：众所周知，比特币是由能够解决复杂数学难题的强大计算机开采的。首先解决难题的矿工可以将下一批交易添加到区块链并收取相关费用。

In the early days of Bitcoin, individual miners competed fiercely for this prize. However, as the network has grown more competitive and the puzzles have become harder to solve, many miners have joined forces and created mining pools. These pools combine the computational power of all their members and then split the rewards among them, regardless of who actually solved the puzzle.

在比特币的早期，个体矿工为了这个奖项展开了激烈的竞争。然而，随着网络竞争越来越激烈，谜题也越来越难解决，许多矿工联合起来创建了矿池。这些池结合了所有成员的计算能力，然后在他们之间分配奖励，无论谁真正解决了难题。

While mining pools can help to stabilize the income of individual miners and make the process of mining more efficient, they can also introduce new opportunities for MEV. For example, if a mining pool were to gain control of a majority of the network hashrate, it could use this power to extract value from transactions by prioritizing certain transactions over others.

虽然矿池可以帮助稳定个体矿工的收入并使挖矿过程更加高效，但它们也可以为 MEV 带来新的机会。例如，如果矿池要获得大部分网络哈希率的控制权，它可以利用这种权力通过优先处理某些交易而不是其他交易来从交易中提取价值。

Out-of-band payments to miners: Finally, another way in which MEV can occur on Bitcoin is through out-of-band payments to miners. This practice involves paying miners (either off-chain, or in a separate and seemingly unrelated bitcoin transfer) to accept transactions which are considered non-standard.

向矿工进行带外支付：最后，MEV 在比特币上发生的另一种方式是通过向矿工进行带外支付。这种做法涉及向矿工付费（无论是链下的，还是单独且看似无关的比特币转账），以接受被认为是非标准的交易。