ON ASSIGNMENT INC

CUSIP: 68215910 Class: COM

ARROWSTREET CAPITAL, LIMITED PARTNERSHIP's Holding History (CIK: 0001164508)

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

Q4 2015
Shares 78,000 Value ($000) $3,506 Avg Close — Range —
Q3 2015
Shares 12,300 Value ($000) $483 Avg Close — Range —
Q2 2015
Shares 12,300 Value ($000) $483 Avg Close — Range —
Q1 2015
Shares 16,558 Value ($000) $635 Avg Close — Range —
Q4 2014
Shares 15,328 Value ($000) $509 Avg Close — Range —
Q3 2014
Shares 40,898 Value ($000) $1,098 Avg Close — Range —
Q4 2013
Shares 234,656 Value ($000) $8,194 Avg Close — Range —
Q3 2013
Shares 156,573 Value ($000) $5,167 Avg Close — Range —