Front-Running: Everything to Know

By  Beluga Research August 5, 2023

Image for Front-Running: Everything to Know


  • Cryptocurrency front-running is the practice of exploiting advanced knowledge of pending transactions to gain unfair advantages in trading
  • Front-running is a manipulative practice in the cryptocurrency market where an individual or entity exploits non-public information to gain an unfair advantage in trading
  • It involves monitoring pending transactions on the blockchain and executing similar transactions with higher fees to profit from price impacts
  • Front-running is considered unethical and unfair, undermining the principles of fairness and transparency in decentralized markets


Cryptocurrency front-running is the practice of exploiting advanced knowledge of pending transactions to gain unfair advantages in trading. The cryptocurrency market operates on the principle of decentralization, which means that transactions occur directly between participants without the need for intermediaries. This decentralized nature has numerous advantages, such as increased security and reduced reliance on centralized authorities. However, it also presents opportunities for certain individuals to engage in manipulative practices like front-running.

A Brief History

Front-running is not unique to the cryptocurrency space and has its roots in traditional financial markets. In traditional finance, front-running typically involves a broker executing orders on behalf of clients while taking advantage of advance knowledge of pending orders from other clients. This practice is considered illegal in regulated markets, as it breaches the duty of the broker to act in the best interest of their clients.

In the context of cryptocurrencies, front-running gained attention with the rise of decentralized exchanges (DEX). A DEX allows users to trade directly with each other using smart contracts, eliminating the need for a centralized intermediary. While this enhances privacy and security, it also opens the door for front-running activities.

Front-Running: Everything to Know

Front-running in the cryptocurrency world occurs when an individual or entity exploits non-public information to gain an unfair advantage in trading. This can happen in various ways, but one common method involves monitoring pending transactions on the blockchain and executing similar transactions with higher fees to ensure their inclusion in the next block. By doing so, the front-runner can profit from the price impact caused by the original transaction.

To execute front-running, sophisticated tools and techniques are often employed. These include bots and algorithms that continuously scan pending transactions on the blockchain and automatically submit transactions with higher fees to outpace other users. Additionally, front-runners may leverage their connections with miners or validators to prioritize their transactions.

The impact of front-running can be significant, particularly in situations where large transactions are involved. By front-running a substantial buy order, for example, the front-runner can drive up the price before the original transaction is executed, resulting in a less favorable price for the buyer. Conversely, front-running a sell order can push the price down, allowing the front-runner to buy at a lower price and profit from the subsequent price increase.

Front-running not only affects individual traders but also undermines trust in the overall market. It creates an uneven playing field, where those with access to privileged information can exploit it for personal gain. This is contrary to the principles of fairness and transparency that cryptocurrencies aim to uphold.

Getting Started

To understand front-running, it's crucial to have a basic understanding of how transactions are executed on a cryptocurrency exchange. When a user places an order to buy or sell a particular cryptocurrency, the order is added to the exchange's order book. The order book is a record of all open buy and sell orders, organized by price and time. When a matching buy and sell order are found, a transaction occurs, and the trade is executed.

Front-running takes advantage of the time delay between when an order is placed and when it is executed. In traditional financial markets, this delay can be attributed to various factors, such as network latency or the time it takes for orders to reach the exchange. In the cryptocurrency world, where transactions occur on decentralized networks, this delay is primarily caused by the time it takes for a transaction to be confirmed on the blockchain.

Unique Aspects

Front-running in the cryptocurrency space has some unique aspects compared to traditional financial markets. One of the key factors is the transparency of blockchain transactions. All cryptocurrency transactions are recorded on a public ledger, allowing anyone to view the details of a transaction, including the sender, recipient, and the amount involved. This transparency provides an opportunity for front-runners to monitor the blockchain for pending transactions and potentially exploit them.

Another unique aspect is the prevalence of decentralized exchanges (DEX) in the cryptocurrency ecosystem. A DEX operates on a blockchain platform and allows users to trade cryptocurrencies directly with each other without the need for an intermediary. Unlike centralized exchanges, a DEX does not have a central authority that manages the order book or controls the trading process. This decentralized nature makes front-running more challenging but not entirely impossible.

Front-running on a DEX typically involves monitoring pending transactions in the mempool, which is a pool of unconfirmed transactions waiting to be included in a block. By analyzing the pending transactions and their associated gas fees (a measure of computational effort required to process a transaction), front-runners can predict which transactions are likely to be included in the next block and take advantage of this information by placing their own transactions with higher gas fees.


  • Profit potential - Front-running allows traders to potentially profit from anticipated price movements resulting from pending transactions. By placing trades ahead of others, they can take advantage of the price impact caused by these transactions and make profitable trades.
  • Timing advantage - Front-runners gain a timing advantage by executing trades before others. This enables them to potentially enter and exit positions at more favorable prices, maximizing their potential gains or minimizing their losses.
  • Information advantage - Front-runners often have access to privileged information about pending transactions, such as large buy or sell orders. This information can be used to make informed trading decisions and capitalize on market inefficiencies.
  • High liquidity opportunities - Front-running can be particularly lucrative in highly liquid markets where even small price movements can result in significant profits. Cryptocurrencies, with their 24/7 trading and high volatility, provide ample opportunities for front-runners to exploit market movements.
  • Scalability - Front-running strategies can be scaled up to handle large volumes of trades, allowing traders to potentially generate substantial profits by executing a high frequency of trades.


  • Unfair advantage - Front-running is considered unethical and unfair because it gives certain traders an advantage over others. It exploits information asymmetry and undermines the principles of fair and transparent markets.
  • Market manipulation - Front-running can contribute to market manipulation by artificially influencing prices through the strategic execution of trades. This can create a distorted market environment and harm other market participants.
  • Increased transaction costs - Front-running often involves executing trades at less favorable prices due to the anticipated price impact of pending transactions. This can result in higher transaction costs for the front-runner, reducing overall profitability.
  • Regulatory concerns - Front-running is a contentious practice that has attracted regulatory scrutiny in traditional financial markets. While the regulatory landscape in the cryptocurrency space is still evolving, it is likely that increased attention will be given to front-running activities, potentially leading to stricter regulations.
  • Reputation risk - Engaging in front-running can damage the reputation of individuals or firms involved. It can erode trust in the market and lead to reputational consequences, which can have long-term negative effects on their business activities.