Trading Information Derivatives Market Market Archives - Client Margin Estimate Reference Table (Stock Options)   February 2010 SUN MON TUE WED THU FRI SAT - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 - - - - - -   January 2010 SUN MON TUE WED THU FRI SAT - - - - - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 - - - - - -