BIOGEN INC

Ticker: BIIB CUSIP: 09062X103 Class: COM

DF DENT & CO INC's Holding History (CIK: 0000934999)

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

Q4 2015

Shares 116,729 Value ($000) $35,760 Avg Close $287.35 Range $254.00 - $311.65

Q3 2015

Shares 203,501 Value ($000) $59,384 Avg Close $330.23 Range $265.00 - $412.24

Q2 2015

Shares 147,364 Value ($000) $59,526 Avg Close $401.33 Range $368.88 - $432.88

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2015	116,729	$35,760	$287.35	$254.00 - $311.65
Q3 2015	203,501	$59,384	$330.23	$265.00 - $412.24
Q2 2015	147,364	$59,526	$401.33	$368.88 - $432.88