don't have a good answer - but frankly it looks to be holding pps pretty well in the face of almost 5x daily volume before noon.
my guess is that since today is the ex-div date, and the shares didn't fall with the market yesterday, you've got a compounding. I'd expect to see a drop of $.45 - so far it is a little more, but in the face of the volume not too bad.
My guess is that a major owner divested itself of its CHI holdings. It may have something to do with the Schedule 13G filing by UBS. A 13G is used to indicate a greater than 5% holding of shares outstanding -- I'm not sure if 13G is also needed when ownership goes below 5%.
My theory is that UBS may need to raise cash to pay the ridiculous fines levied by the US gov't. Sad to see the Swiss knuckle under to Uncle Sam's arrogance.
I came up with the same reasoning, then looked back over past volume after ex div. Nothing like it before ! Must be something we do not know about. Rising interest rates wil hurt CHI but do not see that in the cards any time soon. Something wicked comes this way !