 The role of a scalper is actually the role of market makers or specialists who are to maintain the liquidity and order flow of a product of a market.The profit for each transaction is based only on a few bips (basis points), so scalping is typically conducted when there are large amounts of capital and high leverage or there are currency pairs where the bid–offer spread is narrow.Whenever the "spread is made" one (or more) party must pay it (paying the cost to receive some value on completing the transaction quickly) and some party (or parties) will receive that money as profit.