Antigenics, Inc.

DateInflation Amount Per Share*
2/4/2000**$42.579***
2/7/2000$30.3643
2/8/2000$28.2075
2/9/2000$26.2435
2/10/2000$29.6745
2/11/2000$27.0751
2/14/2000$28.0424
2/15/2000$30.0613
2/16/2000$33.9639
2/17/2000$28.4624
2/18/2000$26.546
2/22/2000$21.7683
2/23/2000$26.8129
2/24/2000$29.7497
2/25/2000$26.79
2/28/2000$21.8161
2/29/2000$26.3036
3/1/2000$28.3608
3/2/2000$27.0471
3/3/2000$26.2615
3/6/2000$25.1371
3/7/2000$26.108
3/8/2000$30.7365
3/9/2000$32.7233
3/10/2000$30.3482
3/13/2000$27.5897
3/14/2000$22.7655
3/15/2000$23.8412
3/16/2000$14.8183
3/17/2000$13.3597
3/20/2000$10.4256
3/21/2000$3.6379
3/22/2000$9.8686
3/23/2000$9.8386
3/24/2000$8.7942
3/27/2000$9.4005
3/28/2000$5.7685
3/29/2000$5.218
3/30/2000$1.0529
3/31/2000$1.3218
4/3/2000$0.8257
4/4/2000$1.1666
4/5/2000$2.2128
4/6/2000$0.7301
4/7/2000$0.483
4/10/2000$0.1783
4/11/2000$0
4/12/2000$0
4/13/2000$0
4/14/2000$0
4/17/2000$0
4/18/2000$0.0107
4/19/2000$0.1744
4/20/2000$0.173
4/24/2000$0.1977
4/25/2000$0.1497
4/26/2000$0.156
4/27/2000$0.0973
4/28/2000$0.3656
5/1/2000$2.2522
5/2/2000$1.331
5/3/2000$1.9057
5/4/2000$2.6194
5/5/2000$2.0337
5/8/2000$2.6883
5/9/2000$2.515
5/10/2000$2.401
5/11/2000$1.5071
5/12/2000$2.9102
5/15/2000$3.0221
5/16/2000$2.8432
5/17/2000$4.8856
5/18/2000$3.5032
5/19/2000$4.7749
5/22/2000$0.8881
5/23/2000$0.2862
5/24/2000$0.1729
5/25/2000$0.095
5/26/2000$0.0157
5/30/2000$0.1088
5/31/2000$0.0197
6/1/2000$0.0453
6/2/2000$0.102
6/5/2000$0.2567
6/6/2000$0.4867
6/7/2000$0.4159
6/8/2000$0.3658
6/9/2000$0.7883
6/12/2000$0.2646
6/13/2000$0.2611
6/14/2000$0.0862
6/15/2000$0.0534
6/16/2000$0.1321
6/19/2000$0.1661
6/20/2000$0.2269
6/21/2000$0.2779
6/22/2000$0.0143
6/23/2000$0.2214
6/26/2000$0.219
6/27/2000$0.2945
6/28/2000$0.3805
6/29/2000$0.3556
6/30/2000$0.3592
7/3/2000$0.2827
7/5/2000$1.5137
7/6/2000$1.4586
7/7/2000$1.1623
7/10/2000$1.1728
7/11/2000$3.4296
7/12/2000$1.7808
7/13/2000$0.6519
7/14/2000$0.7101
7/17/2000$0.4892
7/18/2000$1.0378
7/19/2000$0.425
7/20/2000$0.5089
7/21/2000$0.3698
7/24/2000$0.477
7/25/2000$0.5161
7/26/2000$0.7023
7/27/2000$0.5245
7/28/2000$0.4849
7/31/2000$0.7178
8/1/2000$0.5203
8/2/2000$0.2723
8/3/2000$0.2268
8/4/2000$0.3297
8/7/2000$0.3303
8/8/2000$0.2017
8/9/2000$0.1404
8/10/2000$0.2888
8/11/2000$0.2998
8/14/2000$0.2375
8/15/2000$0.2471
8/16/2000$0.1457
8/17/2000$0.1064
8/18/2000$0.1652
8/21/2000$0.2081
8/22/2000$0.1756
8/23/2000$0.1004
8/24/2000$0.175
8/25/2000$0.217
8/28/2000$0.1941
8/29/2000$0.081
8/30/2000$0.0726
8/31/2000$0.2612
9/1/2000$0.467
9/5/2000$0.5105
9/6/2000$0.3645
9/7/2000$0.2934
9/8/2000$0.2638
9/11/2000$0.161
9/12/2000$0.1844
9/13/2000$0.1655
9/14/2000$0.1203
9/15/2000$0.1381
9/18/2000$0.2461
9/19/2000$0.153
9/20/2000$0.1849
9/21/2000$0.1569
9/22/2000$0.1991
9/25/2000$0.1382
9/26/2000$0.0666
9/27/2000$0
9/28/2000$0.1013
9/29/2000$0.038
10/2/2000$0
10/3/2000$0.04
10/4/2000$0.004
10/5/2000$0
10/6/2000$0
10/9/2000$0
10/10/2000$0
10/11/2000$0
10/12/2000$0
10/13/2000$0
10/16/2000$0
10/17/2000$0
10/18/2000$0
10/19/2000$0.1245
10/20/2000$0.1752
10/23/2000$0.0395
10/24/2000$0
10/25/2000$0.2356
10/26/2000$0.4031
10/27/2000$0.0953
10/30/2000$0.3117
10/31/2000$0.1293
11/1/2000$0.1679
11/2/2000$0.1265
11/3/2000$0.4172
11/6/2000$0.1742
11/7/2000$0.114
11/8/2000$0.0861
11/9/2000$0.0464
11/10/2000$0.0032
11/13/2000$0
11/14/2000$0.0482
11/15/2000$0
11/16/2000$0.0004
11/17/2000$0.1921
11/20/2000$0.0016
11/21/2000$0.0516
11/22/2000$0
11/24/2000$0
11/27/2000$0.0293
11/28/2000$0
11/29/2000$0
11/30/2000$0.007
12/1/2000$0.0602
12/4/2000$0
12/5/2000$2.2808
12/6/2000$0

* Data shown are adjusted forward for all stock splits between the IPO and 12/6/00.

** Purchases on a date not listed in the chart above have no artificial inflation.

*** Purchases in the IPO itself at $18.00 per share have no artificial inflation.