Here's another I developed for buy/hold/sell and shorting as well <a href="http://www.flickr.com/photos/23623637@N05/3476414524/" title="Picture 13 by BT24_7, on Flickr"><img src="http://farm4.static.flickr.com/3366/3476414524_b42780289f.jpg" width="500" height="313" alt="Picture 13" /></a>
Nice, looks like overlays of different period M.A. divergences, correct? Fastest signal up front, progressively slower in the back. Or this could be an overlay of progressively slower time frame divergences. Either way, looks interesting. Let us know how you do with this thing.
Your first guess is the right one. Above the zero line, blue is a buy, green as well. Yellow=hold and when the red histogram starts to turn down, time to start selling the position. it works the same for shorts, just under the zero line. I have a lot more, email me at BT24_7 @ Yahoo.com
A very interesting concept is spreading using the MACD on an array of tick bar intervals and updating the MACD calculation intra bar. This chart is tracking the trend of the MACD on a 40000 to 90000 tick bar chart updating the calculation every 200 ticks and color coding the results of how many of the underlying tick bars are agreeing with the trend, then plotting the results on a very fast 25 tick bar chart. The results are impressive