SMY are only just starting site construction so short term price movements are probably going to be linked with nickel price antics. They are not as undervalued as they were.
However they are likely get rerated again as production of Nickel nears if you are willing to take a 6 to 9 month view.
They are also corporately hungry for additional deals so if they can pull one of those off they could run again. However that is long shot stuff.
acturtle