Arbitrageurs are investors who exploit inefficiencies in the market that arise due to the lag in prices between different exchanges. They act as intermediaries, buying assets at one exchange and selling them at another where the prices are higher. This enables them to benefit off the difference in prices and make a profit. The term ‘arbitrageur’ is derived from the practice of such investors who take advantage of ‘arbitrage’, i.e., the simultaneous purchase and sale of identical assets from different markets with an intention to profit from price discrepancies.

In simplest of terms, arbitrageurs act by buying assets at one market and simultaneously selling them at another, usually within seconds or minutes. In this way they can profit from price discrepancies and make quick money. Arbitrageurs take into account whichever market provides a better price. As different markets boast different prices for the same asset, arbitrageurs identify and facilitate the most efficient price in the global market.

Arbitrageurs are often considered to be one of the most sophisticated investors because of their ability to exploit and identify discrepancies in price between markets. They must be highly knowledgeable of the market's news and must be adept in capitalizing on short-term pricing discrepancies. This requires them to be detail-oriented and have a high level of risk-management, as this activity is often done in a very short time frame.

Arbitrageurs also need to be aware of any possible risks associated with buying and selling assets simultaneously, such as regulatory risks and market liquidity. This can vary on a case to case basis, so full knowledge of the process is essential in order to reap the most benefits.

In conclusion, arbitrageurs are highly skilled investors that identify price discrepancies in the market and act quickly to capitalize on them. With their knowledge of the market, risk-management capabilities and fast-paced nature, arbitrageurs are able to provide an important function to markets that ensures that inefficiencies between markets are ironed out or remain at a minimum.