Integral SIZE uses an external price oracle to calculate execution prices. Depends on the specific pool, the external price oracle can be based on pools in Uniswap v2, Uniswap v3, or SushiSwap. Once an order is submitted on SIZE, the protocol will query the external price oracle to get spot prices over a 30 minute period. By calculating the arithmetic-mean of these prices, the protocol will establish the TWAP to execute your order.