X0202 4 2006-12-20 0000350894 SEI INVESTMENTS CO SEIC 0001101310 MCCARTHY KATHRYN ONE FREEDOM VALLEY DRIVE OAKS PA 19456 1 0 0 0 Common Stock 2006-12-20 4 M 0 30000 9.50 A 30600 D Common Stock 2006-12-20 4 S 0 4800 59.65 D 25800 D Common Stock 2006-12-20 4 S 0 1299 59.60 D 24501 D Common Stock 2006-12-20 4 S 0 200 59.61 D 24301 D Common Stock 2006-12-20 4 S 0 1600 59.62 D 22701 D Common Stock 2006-12-20 4 S 0 200 59.63 D 22501 D Common Stock 2006-12-20 4 S 0 400 59.64 D 22101 D Common Stock 2006-12-20 4 S 0 100 59.65 D 22001 D Common Stock 2006-12-20 4 S 0 1600 59.66 D 20401 D Common Stock 2006-12-20 4 S 0 100 59.67 D 20301 D Common Stock 2006-12-20 4 S 0 100 59.68 D 20201 D Common Stock 2006-12-20 4 S 0 200 59.69 D 20001 D Common Stock 2006-12-20 4 S 0 100 59.76 D 19901 D Common Stock 2006-12-20 4 S 0 800 59.87 D 19101 D Common Stock 2006-12-20 4 S 0 3200 59.81 D 15901 D Common Stock 2006-12-20 4 S 0 100 59.84 D 15801 D Common Stock 2006-12-20 4 S 0 100 59.85 D 15701 D Common Stock 2006-12-20 4 S 0 1 59.86 D 15700 D Common Stock 2006-12-20 4 S 0 500 59.91 D 15200 D Common Stock 2006-12-20 4 S 0 600 59.87 D 14600 D Common Stock 2006-12-20 4 S 0 100 59.90 D 14500 D Common Stock 2006-12-20 4 S 0 200 59.94 D 14300 D Stock Option (Right to Buy) 9.50 2006-11-20 4 M 0 30000 0 D 2005-10-08 2008-10-08 Common STock 30000 6500 D Ruth Montgomery (Attorney-in-fact) for Kathryn McCarthy 2006-12-21