What are good methods or tools to predict or measure the likelihood of side ways price movement X time units forward?
You have to define the length of the trade: is it a day, week, month, year ....similar to a sporting event. Most have a fixed time. And then consider the fixed variables, combined with the dynamic variables that would make that ball line future movement dance. Make your relative assumption bet....and wait patiently for that trigger confirmation. When the moment presents itself...pull the trigger, place the bet. This applies to anticipating upwards movement, downwards movement, or relatively flat movement expectation. The Devil, of course, are in the details. The above is just a quick, rundown, summary of the process. I do this daily with the S&P.
I don't use models (or anyone else's bogus, theorized, system); I have never even heard of those things...nor care to look up what they are. I trade the daily S&P. I use a combination of fixed data points, combined with more dynamic, looser, open-minded, reasonably, intuitive expectations. And for the most part, I'm rather, highly, right. I'm able to buy and sell the major move of the day. If I were to ever teach or sell my process....I would charge a million bucks for my course -- because that's what it's truly worth.
Im truly humbled to be in your presence,but the OP appeared to be asking a question related to trading vol ,I.e predicting the likelihood of a sideways move for a given duration.
Unless one has a crystal ball, nobody really knows for certain. But something like Darvas Box is a good tool to utilize for beginners IMO.
OP,if you are intersted in the likelyhood of price movement from a "modeling" perspective,check out Hoadley's program...Its a bit dated,but you can look at Probability cones,Garch modeling,etc...Its obviously very theoretical,but its what you are looking for...If you want a sure thing,take MacPros course and see if he will offer it for 500k,which is a 50% percent discount..Doubt he bites,but its worth a shot