The basis for me adding a stock to my watch-list falls under one of three conditions:
1) Price and volume pattern offers a promising entry with a low-risk/high reward opportunity
2) Stock has already seen a significant rally in recent days or weeks, but still remains on the list for a possible entry on a light-volume pullback.
3) Stock is one of intrigue to me that I just like to keep it around, in case there is a setup that arises, that is too good to pass up (i.e. AAPL and GS).
Stocks highlighted in yellow are new additions to the watch-list.