What Is Arbitrage trading?
Arbitrage theory:

Have you ever wondered how people profit from selling one commodity in one market when they have bought the same commodity in another? The difference in prices causes most people to profit. In a real example, avocado could be going for $2 in one market and go for $3 in another. If you buy an avocado in the cheapest market and sell it in the next, you will have a $1 profit. You can keep doing this over and over again and continue making more profits. This is the pedestrian explanation of arbitrage. Arbitrage is the simultaneous purchase and sale of a commodity or asset, due to an imbalance in the prices. Securities, commodities or currencies are used in most arbitrage cases.
Arbitrage takes advantage of the price differences, to make a profit. Since no market is efficient, these differences in prices have to exist. The trade of using such differences and making a profit out of it is arbitrage. Arbitrage exists in two broad types: pure arbitrage; and risk arbitrage. Pure arbitrage is risk-free, whereas risk arbitrage is speculative. This is because it is founded on the presumptions of future events that may or may not actually occur. Arbitrage works best in the forex situation, hence the term ‘forex arbitration’.

Arbitrage definition
Arbitrage trading is the process of purchasing securities in one market and immediately selling them in another market, in order to benefit or profit from the differences in prices. You end up with a risk-free profit. Here is a practical example: the stock of Company A is trading at $20 in the New York Stock Exchange (NYSE). The same stock is trading at $20.50 in the Toronto Stock Exchange (TSE). If a trader purchases the stock in the NYSE and sells the stock immediately in the TSE, they will earn a profit of $0.5 per share. This is trading in stocks. The immediate need for purchase and selling is based on the fact that prices can change, which can lead to better profits, no change in the profit margin, or less profit. If the prices adjust and the prices in the LSE go below your purchasing price in the NYSE, you will end up having a loss.

Is arbitrage legal ?
Arbitrage trading is legal. Arbitrage trading can be very profitable. For example you can read articles such as ‘latency arbitrage’ trading maybe $3 billion as same as HFT trading problem is over.

Stock market example: ABC Bank is trading for CAD 74.50 on the Toronto Stock Exchange (TSX), and 56.50 on the New York Stock Exchange (NYSE). At the time, the exchange rate of CAD/USD is 0.77 meaning for every CAD 1, you have USD 0.77. Mathematically, it should mean that ABC Bank’s trade in the NYSE equivalent to USD 57.30. This means that you can purchase ABC’s share from the TSX at CAD 74.50 and sell it in the NYSE at 56.50, making CAD 0.8 profit per share. This is because the New York equivalent of CAD 74.50 is USD 57.30

Latency Arbitrage (High-Frequency Trading Arbitrage)
In this example, we have “slow broker” and “fast broker”. Using HFT trading we can see future price (fast broker) (0.5 seconds faster for example ) and then we can make a profit using “slow broker”.
Latency arbitrage is a complicated way of trading and if you want to learn more you can read research paper Latency arbitrage in fragmented markets.

Concept of arbitrage in the foreign exchange market

What is arbitrage trading in forex?

You can read more in What is Arbitrage Trading in Forex?

Forex Triangular Arbitrage
Forex triangular arbitrage is a method involving offsetting trades in order to profit from differences in the prices of Forex markets. It is a more complicated arbitrage strategy than the ones above. Forex triangular Arbitrage involves a pair of currencies, for example, EUR/GBP, for the Euro and the British Pound. When trading in these pairs, it means that you are buying the first-named currency, while selling the second-named currency. In the example above, you will be buying the Euro, and selling the British Pound. In triangular arbitrage, a trader converts one currency against another, in three banks.
Forex triangular arbitrage example: you have $1,000. You will exchange the money in three banks’ situations, based on the currency exchange values. Take these exchange rates for instance: €/ $ = 0.90; €/ £ = 1.25; and $/ £ = 1.5 respectively. You will convert the $1,000 to Euros, giving you €900. Next, you will convert the €900 to Pounds, and you will get £720. Finally, you will convert the £720 back to Dollars. You will end up with $1,080. You will have earned an extra $80 in the process, assuming there are no transaction costs or taxes.

Technological Advancements in Forex Trading and Arbitrage
In an ever-competitive market, technology has been used to ease the means of acquiring an arbitrage. There are hundreds of trading companies, boasting with experts and excellent software, meant to ease in the day-to-day trading activities. Traders now are able to perform risk-free transactions in a quicker and more agile manner. The arbitrage is still the same, although the strategies used could be different. It is also important to note that each trading software is subject to extra risk, and profitability could change, depending on the software you use. The high number of competitors in the Forex market could mean lower arbitrage. Make sure the software you use is correctly coded, to avoid price quote errors, as well as working with an old version of a program. These tiny errors can cause a lot.
Other Forms of Arbitrage:
Other than the triangular and the forex arbitrage in general, there are several other types of arbitrage. The item in question is the one that varies, however, the concept is still the same.
Interest Rate Arbitrage
This is a common form of arbitrage, also referred to as ‘carry trade’. In this form, an investor sells currency from countries with low-interest rates and then purchases a currency paying higher interest rates. At a later time, the investor reverses the trade, meaning they sell the high-interest rate currencies and purchase low-interest-rate currencies. They get to pocket the difference. This type of arbitrage is carried over a period of time and therefore involves more risk, majorly due to the variation of currencies and/or interest rates.

Spot-Future Arbitrage
The ‘cash and carry’ arbitrage, as it is commonly referred to, involves choosing or taking positions, on the spot and futures markets, with regards to an asset. The trader purchases a particular asset, at a certain price, and sells it in the futures market when the price is much favorable. The reverse of this can also happen, where the trader sells an asset and buys on the same asset in the futures market.
There also is dividend arbitrage, currency arbitrage, fixed-income arbitrage, political arbitrage, regulatory arbitrage and municipal bond arbitrage. All these forms revolve around the term mentioned. For example, dividend arbitrage is where options are purchased out at an equivalent amount of the underlying stock before the ex-dividend date. They are then exercised, collecting dividends. Fixed-income arbitrage profits a trader as a result of pricing differences in interest rate securities. An investor takes opposing positions in the markets, in order to take advantage of price discrepancies, at the same time limiting the interest rate risks.

Problems and Risks in (Forex) Arbitrage
As earlier noted, an arbitrage exists because of the fluctuation in price differences. It is important to be fast about these differences, in order to achieve the desired profit. However, others also recognize the price differences, and under the laws of supply and demand, the price differences shrink. The overpriced items are made to be cheaper, whereas the under-priced ones, have their prices go up. The margin shrinks and the arbitrage becomes no longer profitable. Your execution speeds are very key because they can make the difference as to what amount you will be taking home.
Even in the original example involving an avocado, the prices will fluctuate because of the laws of demand and supply. When the demand is high, the prices go down, whereas when the supply is too high, the prices go high as well. This will cause the cheaper-trading markets to sell their avocados at a more expensive price, while the other market, where they were being sold, will have their prices go down. The arbitrage margins will shrink, causing lower profit margins.
There is also the fact that a ‘negative spread’ can happen. A negative spread is when the seller’s asking price is lower than another buyer’s bid. For example, a bank can quote a particular price for a currency, or a seller can quote a certain price of a product or asset, while another seller or bank, quotes a different selling price. It, therefore, applies that the arbitrageur will purchase from the seller and sell the asset where they can make the most profit. Instead of the trader waiting for a favorable trend in the markets, they encounter one just like that. On the adverse hand, ‘execution risk’ can occur. This is when the price is quickly corrected, making the trade less profitable, meaning the trader could end up having a loss.

Arbitrage examples :
Forex arbitrage between brokers
It is a technique or strategy, using which you will place two separate trades at two different brokers and make money by the price discrepancies. Now the theory is very simple because each broker has its own platform and has a difference in price. In other words, we can say that money can be put together by the difference between two currencies while making pairs of that. Now if the paired money has space to give something then profit is very limited due to the opportunity window.

Using arbitrage strategy as a forex trader?
A strategy that involves no risk in trading in Forex is called arbitrage. It used to profit without currency exposure being open.
This particular strategy is based on aiming for inefficiencies in pricing at the time they are available.
For example, EUR/GBP, EUR/USD, GBP/USD exchange rates are 0,7231, 1,1837, 1.6388. this is the time when you can buy a Euro mini-lot worth 11,837 dollars. Then trade 10thousand euro for GBP and earn 7,231, and then sell that and get 11,850, thus making 13 bucks of profit per trade. Short positions for each currency are canceled by long positions when the exposure isn’t open.
The catch is to act fast, as the inefficiencies with pricing are being corrected quickly. To exploit these inefficiencies, you have to have quotes of pricing in real-time, and you have to be able to quickly exploit the opportunity. There are available calculators to get to these changes faster.
There is a special calculator that can be used to calculate these situations, and it can be found all over the internet, as well as other tools for making finding these inefficiencies easier. Usually, brokers are those who provide these sorts of calculators, sometimes for free, and it can be on a free trial, but they are available.
However, before going for this sort of profiting, you should practice. Demo accounts are good for that job as always.

Due to less risk than other forex techniques or strategies, traders normally prefer to make a transaction. When the risk is too high, the trader will obviously hesitate to put money into the trade or business deal.
Forex arbitrage is the process of profitable trading between two dissimilar forex dealers. Forex (Foreign Exchange) is the conversion of one country’s currency to another country’s currency and ‘arbitrage’ is the term used for increasing profits with a better price difference amongst different country markets. A forex broker is a person who mediates the transactions between two different country persons.
Forex arbitrage involves a currency pair to trade, as one currency is to sell and the other is to purchase. The profits are always in four decimals such as 0.0001$ and as the profits are so minimal, they are called Pips (Percentage in Points). The PIPs may look small, but they value more. Forex arbitrage software, released by Jason Fielder with Anthony Trister and his squad at forex collision, is used to place the trades.

How it works
Forex Arbitrage is a strategy that is used for making money due to the inefficiency in the two currencies and this is done very fast, because when the inefficiency is correct then there is no opportunity to trade-off makes a profit. Real-time currency rates are very important for this because of international market prices changes in minutes, and even seconds.
The most popular trades used in Forex Arbitrage are two currency trades. Now the trader will trade with two different brokers, each with their own pricing spreads. You can make a profit from each transaction by keeping in mind the difference between each broker’s prices for the same currencies in a single quote while keeping an understanding of the currency exchange rate of the two currencies. The exchange rate of the currencies has a smaller ratio than the prices well also checked by the fluctuation of the currency rates.

Arbitrage Calculator
There are a number of techniques used to speed up profits, but the simplest way to do it is with the help of the Forex Arbitrage calculator. The only problem is that they are very expensive, so be very sure that the calculator is working properly before purchasing. The best way to save your money on a Forex Arbitrage calculator is to learn techniques from experienced traders.

The idea behind a Forex Arbitrage calculator is the same but it only automates transactions from different brokers trading in different pairs. There are some big investors who have their own advisory board for huge transactions, but normally two brokers with a single Forex fair. By this software you can keep track of 5 brokers’ pricing feeds along with each currency arbs they are working on.

Forex Arbitrage calculated normally cost from $2000 to $3000, but it also depends on the quality of the software. If it is a high-end product then the price will be more than the standard edition. As advised earlier, before purchasing a calculator it is better to check the demo version to give you an idea of what to expect.
Let’s take an example of how it works theoretically with the help of three related currencies paired by the formula.
AAA/BBB x CCC/AAA = CCC/BBB
BBB = USD (US Dollar)
AAA = EUR (Euro)
CCC = GBP (Pound Sterling)
You can make profits from purchasing US Dollars and spend it but buying Euros, then once again buying Pounds Sterling by spending US Dollars and at the end by selling CCC with the pair of Euro; by making all this process a small amount of profit will be earned. You can also increase the profit by trading higher amounts for different brokers with a margin of prices.
You will probably have noticed that this technique is simple in theory but sophisticated in the application. If you have patience and have complex software that can formulate the huge amounts and exchange rates, then you have a little opportunity to make money because there are so many traders extracting similar information. Forex Arbitrage only supports your income but it can not run your expenses.

Conclusion
Markets are dynamic, and they change every second. A trader can potentially lose or gain from any change in the markets. Executing arbitrage measures can be potentially profitable, but in certain situations, it can lead to losses. The advancement in technology has made it easier for traders to be able to generate profits in the Forex trading circles. However, caution should be exercised, since the increasing number of players in the markets, makes the arbitrage margins fluctuate. Such fluctuation can lead to losses, exceeding the amounts deposited. It, therefore, is imperative for traders, to check the news, prices, research, analysis, and other information provided relating to general market trends. However, they should stay away from investment advice as it may be clouded or wrong.