A change to Ethereum could make a new group of crypto kingpins.

The long-awaited update to Ethereum will add new people to the blockchain ecosystem, who will be called builders. This could change the power structure of what is arguably the most important cryptocurrency network for business.

Under the current system, networks of computers called "miners" pull transactions from a special data pool and put them into blocks, which are then added to the blockchain.

As part of a plan to cut down on energy use, the miners are being fired.

After the Merge update, which is set to happen in September, the builders will put transactions into blocks and send them to the validators.

The validators will agree on the order of the blocks that will make up the upgraded blockchain by signing their names.

This geeky-looking change, which is part of an upgrade to the software called MEV-Boost, could make Ethereum more centralized, at least at first.

Even though there are already more than 416,000 validators ready to process transactions, only a few people have signed up to be builders.

Flashbots is the biggest. It makes open-source software that trading bots use.

Flashbots is already the most common way for miners to get fees from traders. They do this by letting traders' transactions run ahead of others' and get around them.

Others are thinking about becoming builders because they are afraid that Flashbots or similar entities will have too much power.

"It kills decentralization," said Uri Klarman, the CEO of BloXroute Labs. His company has a network of servers that make it easier for traders to send transactions to miners.

About 40% of all the trading volume from decentralized finance apps, which let people trade, loan, and borrow coins, goes through the network, he said.

Klarman said that one risk is that a powerful digital wallet that lets users buy, sell, and receive cryptocurrency, like MetaMask, could become a "kingmaker."

With 30 million users, MetaMask is the most popular wallet that doesn't hold your money.

Klarman said that a wallet service could choose to favor one builder over all the others or even become a builder itself to control the flow of transactions.

MetaMask is owned by ConsenSys, which is based in New York and was started by Joseph Lubin, who also started Ethereum. The software company says that the worry is unfounded.

Taylor Monahan, the global product lead at MetaMask, said, "We will never send all of MetaMask's transactions to a single builder or provider."

"MetaMask's value comes from the fact that it is a doorway to a fun, lively, diverse, and fair ecosystem.

MetaMask will always try to make decisions that support a healthy, decentralized Ethereum because of this.

The role split between builders and validators was first thought of as a way to make Ethereum more decentralized and take power away from validators.

Still, there could be problems if there aren't enough builders on the upgraded Ethereum chain.

They could stop certain transactions from going into blocks.

After the US Treasury Department approved the mixer protocol, Tornado Cash wallets were taken off Flashbots' list at the beginning of this month.