For instance, if we take a less active period between 5 pm – 7 pm EST, after New York closes and before Tokyo opens, Sydney will be open for trading but with more modest activity than the three major sessions (London, US, Tokyo). Consequently, less activity means less financial opportunity. If you want to trade currency pairs like EUR/USD, GBP/USD or USD/CHF you will find more activity between 8 am – 12 am when both Europe and the United States are active.
Governments / Central banks – A country’s central bank can play an important role in the foreign exchange markets. They can cause an increase or decrease in the value of their nation’s currency by trying to control money supply, inflation, and (or) interest rates. They can use their substantial foreign exchange reserves to try and stabilize the market.

Foreign exchange fixing is the daily monetary exchange rate fixed by the national bank of each country. The idea is that central banks use the fixing time and exchange rate to evaluate the behavior of their currency. Fixing exchange rates reflect the real value of equilibrium in the market. Banks, dealers, and traders use fixing rates as a market trend indicator.
International parity conditions: Relative purchasing power parity, interest rate parity, Domestic Fisher effect, International Fisher effect. Though to some extent the above theories provide logical explanation for the fluctuations in exchange rates, yet these theories falter as they are based on challengeable assumptions [e.g., free flow of goods, services and capital] which seldom hold true in the real world.
The bare bones of foreign currency exchange trading are simple. You make money off exchanging one country’s money for another. However, exploiting those fluctuations or price movements requires both strategy and savvy. Signing up for online tutorials or in-person conferences will help you lay a base layer of knowledge on the forex market, but traders agree that true expertise is built on the job. Jump in to a demo or a real (small sum) account and start hitting buttons, pulling from vast online resources whenever you hit a snag or just a big, fat question mark.
From Monday morning in Asia to Friday afternoon in New York, the forex market is a 24-hour market, meaning it does not close overnight. This differs from markets such as equities, bonds, and commodities, which all close for a period of time, generally in the New York late afternoon. However, as with most things there are exceptions. Some emerging market currencies closing for a period of time during the trading day. 

Automated Forex trades could enhance your returns if you have developed a consistently effective strategy. This is because instead of manually entering a trade, an algorithm or bot will automatically enter and exit positions once pre-determined criteria have been met. In addition, there is often no minimum account balance required to set up an automated system.

Forex alerts or signals are delivered in an assortment of ways. User generated alerts can be created to ‘pop up’ via simple broker trading platform tools, or more complex 3rd party signal providers can send traders alerts via SMS, email or direct messages. Whatever the mechanism the aim is the same, to trigger trades as soon as certain criteria are met.

None of the models developed so far succeed to explain exchange rates and volatility in the longer time frames. For shorter time frames (less than a few days), algorithms can be devised to predict prices. It is understood from the above models that many macroeconomic factors affect the exchange rates and in the end currency prices are a result of dual forces of demand and supply. The world's currency markets can be viewed as a huge melting pot: in a large and ever-changing mix of current events, supply and demand factors are constantly shifting, and the price of one currency in relation to another shifts accordingly. No other market encompasses (and distills) as much of what is going on in the world at any given time as foreign exchange.[74]
The most favorable trading time is the 8 AM to noon overlap, when both New York and London exchanges are open. These two trading centers account for more than 50% of all forex trades. On the flipside, from 5 PM to 6 PM EST, the only operation open for business is the Singapore exchange, which accounts for less than 10% of annual forex trading volume. But there an be exceptions. Political or military crises that develop during this hour, could potentially spike volatility and trading volume, making this window a favorable time to trade.
National central banks play an important role in the foreign exchange markets. They try to control the money supply, inflation, and/or interest rates and often have official or unofficial target rates for their currencies. They can use their often substantial foreign exchange reserves to stabilize the market. Nevertheless, the effectiveness of central bank "stabilizing speculation" is doubtful because central banks do not go bankrupt if they make large losses as other traders would. There is also no convincing evidence that they actually make a profit from trading.
In the futures market, futures contracts are bought and sold based upon a standard size and settlement date on public commodities markets, such as the Chicago Mercantile Exchange. In the U.S., the National Futures Association regulates the futures market. Futures contracts have specific details, including the number of units being traded, delivery and settlement dates, and minimum price increments that cannot be customized. The exchange acts as a counterpart to the trader, providing clearance and settlement.