[isatrader]

Ok thanks, I think I'm misunderstanding how these are set-up. So the momentum index is the moving average of the A/D line oscillating around a zero line (not the A/D line oscillating around a zeroed 52 week average? as I believe mine above is).

Yes, it's just a 200 day moving average of the daily advances minus the declines. Attached is a one year chart of how the chart looks with the Advances minus the Declines not hidden. It's the same chart, and the blue line is the momentum index (200 day MA) that you could see on the previous chart, so the straight data is hidden as it oscillates wildly every day from plus to minus figures and only 200 day MA is then used to create the momentum index.