# Comparison with order book exchanges

Perpetual Protocol is an AMM-based DEX, making trading somewhat different from the traditional order book exchange model seen in traditional finance and early Ethereum DEXs.

#### Makers and Takers

Every trade is made with the Perpetual Protocol vAMM as the maker. However, there are no additional fees for trading as a taker.

This is one of the nice features about the vAMM model (and what makes our limit orders different to orders on other sites). If you place a limit order to buy 1 ETH at $2000, then you will be the taker and the vAMM will be the maker.

Functionally, with a vAMM a limit order to buy 1 ETH at $2000 is the same as saying "Place a market order for 1 ETH only when the price is below $2000." So it is quite likely that you actually get a better price than your order asked for. 

#### Example

If ETH drops from $2001 to $1950 suddenly (ie. in 1 block), then Apex will execute your order at the current price of $1950.