I own both. I am doing nicely with GTAT & GLW. I don't see a zero sum game here.
I have a $25k basis in GLW. I predict with very high confidence market beating returns in the years to come. GLW is the epitome of a value investment.
GTAT is a growth chaser. I now have a $20k basis here. As the GTAT story unfolds, it's getting more positive. If indeed Apple adopts sapphire significantly, GTAT will be a serious multi-bagger. My 1st GTAT $5k position has returned 175% in 18 months. I recently added the other $15k, so I am now averaged in at $7.78.
Yes, I can lose it all if sapphire fails. But I think the odds are that sapphire will be a decent market. It will give GTAT more runway with which to await solar markets rising again. Meanwhile, I'll keep making money in GLW.
Sapphire was the wife of George Kingfish Stephens on Amos and Andy. When you invest in sapphire you are helping perpetuate a stereotype of an angry black women. Stay with Corning and you will not risk perpetuating this stereotype.