If I wanted to trade 4 currency pairs all as one position, what would I have to do to set up Bollinger Bands to track the whole position? most likely I'd be using sierra charts
You would need to form a composite chart of your pairs. I.E. a synthetic index, and then plot your bands against that.
How do you plan to use the BBs? = = = = = = = = = To detect each pair's transition between trend and chop? In which case, setting BBs up as per normal (i.e. each BB set up done independently for each pair on its own chart for that pair) could be the way forward. Or, to detect some composite signal coming from the relative price behaviours of all four currency pairs together? Something like putting BBs on an index based instrument, like SPY or the ES mini? In this case, you need to construct a currency index for your pairs, as the last poster suggested. There are probably lots of ways to do this, but I believe it generally involves chosing one currency as the base currency (I guess the base currency doesn't even have to be one of the four currencies you are looking at???), and a weighting for combining each constituent into the index (e.g. relative GDP, or something like that???). Then you just calculate your index at each point in time that you are interested in, the moving average of these index values, and the standard deviations ... and there you'll have BBs for your four currencies. Is that what you are looking for?
yes, where I got stopped was the realization I'd have to create a synthetic index. Yes, I always have one base currency, although it changes from time to time. I trade them for the most part as one portfolio, but I wanted the bands to identify a good entry point. Bands on the individual pairs won't work. Creating an index is kind of baffeling, since all the pairs have different pip values.