ALEXION PHARMACEUTICALS INC

CUSIP: 015351109 Class: COM

VIKING GLOBAL INVESTORS LP's Holding History (CIK: 0001103804)

Note: Option positions (PUT/CALL) are excluded.

Q2 2015
Shares 201,756 Value ($000) $36,471 Avg Close — Range —
Q4 2014
Shares 390,271 Value ($000) $72,212 Avg Close — Range —
Q3 2014
Shares 2,198,451 Value ($000) $364,547 Avg Close — Range —
Q2 2014
Shares 2,006,092 Value ($000) $313,452 Avg Close — Range —
Q1 2014
Shares 1,836,658 Value ($000) $279,411 Avg Close — Range —
Q4 2013
Shares 2,877,008 Value ($000) $382,308 Avg Close — Range —
Q3 2013
Shares 3,454,640 Value ($000) $401,290 Avg Close — Range —
Q2 2013
Shares 5,544,949 Value ($000) $511,466 Avg Close — Range —