MEV in Binance Builder
This paper empirically demonstrates that Binance's whitelisted Proposer-Builder Separation design on BNB Smart Chain has led to extreme centralization, where two dominant builders control over 87% of blocks and 90% of MEV profits by exploiting short block intervals and private order flow to eliminate competition and exacerbate fairness issues.
Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Imagine the BNB Smart Chain (BSC) as a high-speed, exclusive casino where the house (the blockchain) runs a game called "MEV" (Maximal Extractable Value). In this game, players try to find tiny price differences between different token exchanges and make a quick profit by swapping them back and forth.
This paper is a detailed investigation into who is actually winning this game and how the casino is rigged.
Here is the breakdown of their findings using simple analogies:
1. The Setup: A "Whitelisted" VIP Club
On the Ethereum blockchain (the bigger, older casino), anyone can try to be a "builder" (the person who organizes the transactions for a new block). It's like an open market where anyone can set up a stall.
But on BSC, the rules are different. It's a private, members-only club.
- The Gatekeepers: Only a tiny list of "whitelisted" builders are allowed to play.
- The Speed: The game moves incredibly fast. A new "hand" (block) is dealt every 3 seconds. On Ethereum, it takes 12 seconds.
- The Backdoor: Instead of shouting orders in a public square (the public mempool), these VIP builders have a direct phone line to the dealer (the validator). They can send their orders privately before anyone else even knows the game has started.
2. The Result: A Two-Headed Monster
The researchers tracked the casino for almost a year. They found that the game isn't competitive; it's a monopoly.
- The Winners: Two builders, named 48Club and Blockrazor, are the only ones who really matter.
- The Stats: Together, they build 87% of all the blocks. They take home 90%+ of the profits.
- The Analogy: Imagine a race where 100 people show up, but two of them are driving F1 cars on a track, while the other 98 are walking. The two drivers win every single race, and the walkers never even get close to the finish line.
3. How They Win: The "Short-Cut" Strategy
The researchers looked at how these two giants make their money.
- Simple Routes: They don't take long, complicated journeys. They mostly do quick, 2-to-3-step swaps (like trading USDT for WBNB, then for USD1, then back to USDT).
- The Profit: Most of the time, the profit is tiny (pennies). But because they do it millions of times, they make millions of dollars.
- The "Secret Sauce": Because they have the private phone line and the fastest computers, they see price gaps the moment they appear. By the time a regular person (a "searcher") even notices the price difference, the VIP builders have already snapped it up.
4. The Structural Problem: The "Missing Horizon"
This is the most important part of the paper. The authors argue that the 3-second speed limit of BSC breaks the fairness of the game.
- The Analogy: Imagine a race where the finish line is only 10 meters away.
- Ethereum (12 seconds): The race is long enough that if you trip, someone else might catch up, or you can change your strategy. There is time for a "second chance."
- BSC (3 seconds): The race is so short that if you are 0.1 seconds slower than the person next to you, you lose everything. There is no time to react.
Because the window is so tiny, latency (speed) is the only thing that matters. If a builder is slightly faster or has a better connection to the dealer, they win 100% of the time. This creates a "Missing Horizon"—a period of time where competition could happen, but the rules of the game make it impossible.
5. The Consequences: Censorship and Inequality
Because the two big builders control almost everything:
- They can ignore people: If a regular user tries to send a transaction, the builders can simply choose not to include it in their block if it doesn't help them make money.
- They control the assets: Most of the money flowing through these trades is in "stablecoins" (like USDT and USDC). These tokens can be frozen by their issuers. So, the entire system relies on assets that can be shut down by a central authority.
- The "Rich Get Richer": The system is designed so that the people with the fastest computers and the best private connections get richer, while everyone else is left with scraps.
Summary
The paper concludes that Binance's version of the blockchain is much more centralized and less fair than Ethereum's.
It's not just that a few big players are winning; it's that the rules of the game (3-second blocks + private access) are mathematically designed to ensure that only the fastest, best-connected players can ever win. It turns a competitive marketplace into a private club where the house and its VIPs take almost all the money, leaving ordinary users with almost no chance to compete.
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