Is there a way to trade the US Dollar Index on Interactive Brokers? If so, may I ask, what symbol that would be?
You don't want to. Its a "basket index" and is very thin. Trade the actual pairs that real people exchange currencies in: eur-usd usd-jpy eur-jpy gbp-usd aud-usd gbp-eur etc to get valid movements rather than some mathematical construct.
The NYBOT Dollar Index futures contract trades electronically on the ICE platform (www.theice.com), and futures and options still on the floor of NYBOT. DX is the floor symbol; on my platform the electronic symbol is IDX. Boy Plunger is right about the US hours profile. I trade a few contracts occasionally during late Asian & European hours, and the b/a is often just one or two ticks wide. 2k to 3k is typical daily volume for the front month, the bulk of it on ICE now. Kiwi, you trade the HSI, don't you? Isn't that a 'mathematical construct'?! (as they're about to reconfigure it again...) If you want to express a dollar-directional view, then the DX is an appropriate contract. Plus - for some traders - it has advantages of lower volatility, tick size, margins etc.