I think I'd be pressured to sell at that point. I"m looking at CSUN right now as the best value in the solar power market. It has a PE that should be updated to around 20, with an incredibly torrid growth rate (which will slow). It's a good dual play on the yuan/dollar and solar market.
So basically, if we hit 50 on a good earnings, I'm going to sell 50% and send it over to a company which works with the yuan and NOT the dollar (according to The Economist, some models show the yuan at 40% undervalued, while others show it fairly valued; so lets imagine it's 20% undervalued. UUU is a fantastic stock to hold in the low 30's, but it's only pretty good at 50, imo. Only earnings of 2.0 million and encouraging guidance would cause me to be a holder at 50.