$NYAD is an important breadth indicators, it gives us a good idea of where the market is moving. It can show if there is strength in the move up.
The latest short-term trend in NYAD has been down, but today it moved up. Coming close to its 8 day EMA. This was important support during the move up in March to May, since the market peeked at 950 NYAD has been climbing down, dropping below its 8EMA. The real pattern emerges what happens after the NYAD drops below its 8EMA.
When the $NYAD move is capped by the 8EMA, the market typically has a down day the next day. When the market climbs above it, it has an upday. But I think the more important thing to look at on this chart is how the 8EMA caps a move and then starts a trend.
The NYAD is already in a downtrend, if it would not be able to get above the 8EMA and start a move up, we could see further downside.
Another possible pattern on the NYAD is the formation of the moving averages. The have started to flatten and possibly are rolling over. If you look at a longer-term chart, you can see what happens when the moving averages move down. NYAD is already below its 8 and 19EMA's a break of the 39 would be bearish.
The reason I use the 19 and 39 is that these EMA make up the $NYSI which is a longer-term indicator.
It has been on a steady decline downwards since late May. It's moving averages look to have the possibility to cross as well. As this gets closer to zero it will become more important to watch.