In business economics, finance and sports, arbitrage is the method of taking advantage of a cost difference between several markets: striking a variety of matching deals that capitalize upon the asymmetry, the gain being the difference amongst the market prices.
When utilized by academics, an arbitrage can be described as transaction that involves no damaging cashflow at any probabilistic or temporal state along with a positive income in one or more state; simply, it is the probability of a risk-free profit at zero cost.
In principle as well as in academic use, an arbitrage is risk-free; in common use, for example statistical arbitrage, it may refer to predicted profit, though losses may happen, and in practice, there are always risks in arbitrage, some minor (such as change of prices decreasing income), some major (for example devaluation of the currency or derivative).
In academic use, an arbitrage involves taking advantage of variations in cost of a single asset or identical cash-flows; in common use, it is also used to make reference to differences between similar assets (relative value or convergence trades), as in merger arbitrage.
Individuals that participate in arbitrage are called arbitrageurs perhaps a bank or brokerage firm. The term is especially related to trading in financial instruments, including bonds, stocks, derivatives, commodities and currencies.
Sports arbitrage has also recently become possible mainly because of the availability of web-based bookmakers supplying widely diverging odds on sporting events creating situations where it is possible to where you can’t lose
Although this involves bookmakers this isn’t gambling as there isn’t any risk to the initial stake which cannot be lost. These betting systems or betting strategies are called ‘Arbitrage Betting’ or ‘Matched Betting’
Arbitrage isn’t simply the act of purchasing an item in one market and selling it in another for a larger price at some later time. The transactions must happen simultaneously to protect yourself from exposure to market risk, or even the risk that prices may change in one market before both dealings are finished.
In simple terms, this can be generally only possible with securities and financial products which may be traded electronically, and even then, when each leg of this trade is accomplished the prices in the market could have moved.
Missing one of the legs of the trade (and subsequently having to trade it soon after at a worse price) is called ‘execution risk’ or more specifically ‘leg risk’.
“True” arbitrage mandates that there be no market risk concerned.