I know your question was put to Col specifically - but I'd like to just say that UMC is the last share I'd be 'trading'. I've been in it for several years now and I've noticed a couple of things... firstly if I'd sold on the day before just about any positive news and then bought back in I'd be way in front, and secondly unlike some companies you can't necessarily gauge the buy/sell on world markets - there just hasn't been those institutions involved that add that scope of predictability.
I'm by no means offering advice, these are just my observations as an 'investor' (that squirms with hindsight like most I imagine).
Good luck mate.
UMC Price at posting:
88.0¢ Sentiment: Buy Disclosure: Held