This isn't an indicator. It is a composite. It is very important that you read the item description. You will see there that you need advance/decline data in order to calculate the TRIN composite.
Once it is calculated, a new symbol whose name is "_ARMS INDEX" is created (Info available in the item description too)
Note these items are created by QuantShare members.
Trading financial instruments, including foreign exchange on margin, carries a high level of risk and is not suitable for all investors. The high degree of leverage can work against you as well as for you. Before deciding to invest in financial instruments or foreign exchange you should carefully consider your investment objectives, level of experience, and risk appetite. The possibility exists that you could sustain a loss of some or all of your initial investment and therefore you should not invest money that you cannot afford to lose. You should be aware of all the risks associated with trading and seek advice from an independent financial advisor if you have any doubts.