A traditional advance-decline line compares the number of stocks which have closed up for the day to the number which have closed down for the day. This can be a quick way to view the strength of the market. Most people display this number on a graph. Because this number is so noisy, many people apply moving averages and other analytics on top of the advance-decline line.
We focus on real-time, intra-day analtyics. Our users can create their own intra-data advance-decline lines. Just create two alert windows side by side. Configure one to show bullish alerts and the other to show the corresponding bearish alerts. To create a more traditional advance-decline line, choose a simple alert like 10 minute highs and lows. For a more focused approach, use alerts like running up and down which reqire statistical validation.
For the instantaneous view of the market, see which window is scrolling the fastest. For a slightly longer term approach, hit the refresh button in each window when the market makes an important turn. That will reset the counters in each window. Watch the counters over time to see if the bulls or the bears are winning since the last reset.
If you do not set any other filters, you will compute something very similar to a traditional advance-decline line. Most users will restrict the universe of stocks to show only stocks that they trade.
Another option is to put both the bullish and the bearish alerts into the same window. This way you can react to the color of the window, like a heat-map, rather than looking at numbers.