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# Frontrunning

**Transactions are not instantaneously added to the blockchain**. First, they are **publicly transmitted to the nodes in the network** and **added to a pool of pending transactions**. Later, they are added to a block and official become part of the distributed ledger

**Priority** is often given to transactions with a **higher fee**

This enables frontrunning attacks. **After observing a transaction, an attacker can create one with a higher fee.** This malicious transaction will likely be processed first

Frontrunning attacks can be used for a variety of purposes, like making a profit or winning a contest