Inspired by the poetic stylings of W.B. Cypher to make a buck before mere anarchy is loosed upon the world, I was looking at some of the daily London Fix data. I noted that the minimum gold price in a given month has been a linear function of its monthly maximum and median price, with min = a + b*sqrt(max)*median^2 fitting damn well.
You see where I'm going here? As soon as a month is half-finished, we know what the lowest possible median can be ($1628.60 this month), and we know what the lowest possible maximum can be ($1674.25 this month), so we should be able to predict a floor to the monthly price with great accuracy and precision.
