Can someone tell me the difference between these 2 MRK Jan 2006 calls at 27.5.
Calls LastSale NetChg Bid Ask Vol OpenInterest
JAN 2006 27.5
MRKAY 2.60 1.40 2.30 2.60 262 7,674
JAN 2006 27.5
WMRAY 6.60 0.20 6.60 6.80 29 7,780
I got AY means Jan 27.50, MRKAY makes...