The term "liquidity" is used a lot in trading and finances since it is a vital aspect of market behavior. However, people often use this term very liberally in forex trading often without understanding its exact meaning and the implications of high or low values of this particular property. On this article I want to explain to you what the term "liquidity" is, what it exactly means, its implications within a given instrument and why it is such an important characteristic of the market.
Imagine that we had 20 people standing on a circle with 19 of them holding empty glasses and one of them holding a glass full of water. Now we want to see how much time it will take for the person with the glass to pour it onto the next one and so on until the water reaches him/her again. What we find is that it takes a long time for the water to be exchanged along the full circle because only 2 players are able to participate (the one holding and the one receiving) while all the others have to stay on the sidelines, waiting for their glass of water. Now imagine that we give half of them a glass of water, the process is much faster since the number of active participants has now increased to include everyone, all the people are actually exchanging water all the time.
Liquidity on the market is nothing else than the "water" in the above example, it is the amount of volume exchanged of a given instrument over a given amount of time. When there is high liquidity there is a lot of volume being exchanged and when there is low liquidity there is little volume being exchanged. When we have a lot of volume people can get in and out of the market easily (since there is always a buyer for every seller and vice versa) while when there is low liquidity the market gets "stuck" as people have to fight to get in or out of their positions. When there is low liquidity you also get harsher price movements since a person holding a position may be forced to drastically change the offering price to match what the other end - which is very scarce - wants. So while under high liquidity exchanges are easy and swift, under low liquidity prices move more erratically since the offered and accepted prices tend to have larger gaps between them. The consequences for the little trader are unpredictability and spread widening while for the large players the consequences are mainly not being able to get in or out of positions due to the lack of available exchange capacity.
Liquidity in the forex market is extremely difficult to read and study since the market has no central exchange but it is handled over a wide variety of banks worldwide in an over-the-counter manner. The volume of a given contract that has been exchanged during a certain period of time therefore becomes hard to read since it depends on the particular provider you are talking about. Even though the market is praised as being extremely liquid and huge, the fact is that this is only be true if you can access to all - or a lot - of liquidity providers (banks). If you limit yourself to just a few you will see that the liquidity you have access to is nowhere near the trillions of dollars people talk about.
When we are going to trade the foreign exchange market, knowing the liquidity levels of the instruments we want to trade is important since currency pairs with higher liquidity tend to be "easier to trade" since they show more inefficiencies characteristic of crowd behavior while instruments with low liquidity tend to show a more random walk much more characteristic of individual investor behavior. Therefore, instruments that are very liquid tend to be easier to exploit using mechanical trading systems while those that don't tend to be much harder to trade. However, as the time frames get bigger liquidity starts to become a less important factor and crowd-based inefficiencies still arise. This is the main reason why you should look for strategies based on larger time frames and longer period indicators when attempting to design systems for illiquid instruments.
On tomorrow's post I will discuss the inner aspects of liquidity in the forex market a little bit more, I will discuss some of the currently available literature about the subject in economics and the liquidity characteristics of different currency pairs. If you however would like to learn more about automated trading and how you too can start designing and programming your own systems based on realistic and sound strategies please consider buying my ebook on automated trading or joining Asirikuy to receive all ebook purchase benefits, weekly updates, check the live accounts I am running with several expert advisors and get in the road towards long term success in the forex market using automated trading systems. I hope you enjoyed the article !