## Unveiling the Dark Side of DeFi: How MEV Bots Profit Through Sandwich Attacks

Behind the scenes of blockchain transactions, a silent war is underway. **MEV bots** (Miner Extractable Value bots) exploit a technique called sandwich attacking, repeatedly extracting profits from ordinary users day after day. While this phenomenon may seem complex, it actually reflects an unavoidable reality within the DeFi market.

### What is MEV and the True Nature of MEV Bots

MEV stands for Miner Extractable Value, referring to arbitrage opportunities with positive expected value that are obtained through automated interactions on the blockchain. It differs from price speculation, is not a traditional investment product, and is certainly not a Ponzi scheme. To put it more intuitively, **MEV bots play a role in DeFi similar to high-frequency trading (HFT) in traditional stock markets**—profiting through information asymmetry and transaction ordering rights.

The most notorious MEV operator currently is the Ethereum address jaredfromsubway.eth. This account's bot has executed over 238,000 transactions, affecting more than 106,000 users. These figures highlight the enormous scale of MEV bots.

### Sandwich Attacks: The Most Common Exploitation Method in DeFi

The core operation of MEV bots is **sandwich attacking**, which is also the most controversial MEV implementation method today. In simple terms, this attack involves inserting one of the bot's own transactions before and after a target user's transaction, forming a "sandwich" structure to profit from the price movement. This strategy is very similar to front-running tactics used by high-frequency traders.

In the DeFi community, sandwich attacks are often criticized as a toxic element damaging ecosystem health. However, a more comprehensive view reveals that while they have obvious harms, they also possess certain economic rationality.

**From a negative perspective**, sandwich attacks are pure exploitation targeting information asymmetry users. Retail traders who lack understanding of blockchain mechanics or are unaware of slippage settings are the easiest targets. Especially when purchasing new tokens, users often set extremely high slippage tolerances (sometimes up to 99%) to ensure transaction success, effectively inviting MEV bots to exploit them.

**From a positive perspective**, analyzing from an economic efficiency standpoint, operators of sandwich bots seem to push token prices toward market equilibrium. This mechanism helps the market reflect consumers' maximum willingness to pay and creates space for value extraction by operators. Although their ultimate goal is profit, this process also contributes to optimizing market pricing efficiency.

### Can Sandwich Attacks Be Truly Avoided?

Unfortunately, the answer is no. As long as there is an economic incentive for MEV arbitrage, sandwich attacks cannot be completely eliminated. If you do not run an MEV bot, others will. This is an inevitable market-driven outcome; as long as transactions exist, such behaviors will continue.

In fact, similar front-running behaviors have long been present in traditional stock markets and are recognized as normal. Therefore, even at this very moment, sandwich attacks in DeFi are ongoing continuously.

### Technical Countermeasures: The Rise of FlashBots

While complete prevention is impossible, the industry has begun exploring new solutions. **FlashBots** is one such tool—it is another form of bot capable of hiding transaction information from MEV bots. Currently, a technical game is underway between traditional MEV bots and FlashBots, signaling the future direction of DeFi security defenses.

### Summary

MEV bots and their sandwich attack phenomena reflect both the vibrancy and risks within the DeFi market. Understanding how these mechanisms operate helps users better protect their assets. In this rapidly evolving ecosystem, participants need to enhance their awareness, carefully set transaction parameters, and pay attention to advances in technical safeguards.

**Disclaimer**: This article analyzes the MEV phenomenon solely from technical and market perspectives and does not constitute any investment advice. Investing involves risks; please make rational judgments and comply with relevant laws and regulations in your region.