| Top Institutional Holders |
|---|
| Holder | Shares | % Out | Value* | Reported |
|---|
| Perceptive Advisors LLC | 5,630,000 | 8.39 | 11,485,200 | 2013-03-31 | | Baker Brothers Advisors, LLC | 4,775,787 | 7.12 | 9,742,605 | 2013-03-31 | | Columbia Wanger Asset Management, L.P. | 4,302,458 | 6.41 | 8,777,014 | 2013-03-31 | | VHCP Management, LLC | 2,516,870 | 3.75 | 5,134,414 | 2013-03-31 | | Vanguard Group, Inc. (The) | 2,016,957 | 3.01 | 4,114,592 | 2013-03-31 | | BlackRock Institutional Trust Company, N.A. | 1,300,796 | 1.94 | 2,653,623 | 2013-03-31 | | Royce & Associates, LLC | 710,000 | 1.06 | 1,448,400 | 2013-03-31 | | TFS Capital LLC | 608,742 | 0.91 | 1,241,833 | 2013-03-31 | | Jacobs Levy Equity Management, Inc. | 588,829 | 0.88 | 1,201,211 | 2013-03-31 | | J. Goldman & Co., L.P. | 441,250 | 0.66 | 900,150 | 2013-03-31 |
|
| Holder | Shares | % Out | Value* | Reported |
|---|
| Columbia Acorn Fund | 2,798,416 | 4.17 | 5,708,768 | 2013-03-31 | | Vanguard Extended Market Index Fund | 1,113,301 | 1.66 | 2,271,134 | 2013-03-31 | | Royce Micro Cap Trust | 710,000 | 1.06 | 539,600 | 2012-12-31 | | Vanguard Total Stock Market Index Fund | 636,886 | 0.95 | 1,299,247 | 2013-03-31 | | Columbia Acorn USA Fund | 419,511 | 0.63 | 855,802 | 2013-03-31 | | Wanger Advisor Trust-Wanger USA, Variable Series | 246,255 | 0.37 | 502,360 | 2013-03-31 | | TFS Capital Investment Tr-Tfs Market Neutral Fund | 188,248 | 0.28 | 156,245 | 2013-01-31 | | Spartan Extended Market Index Fund | 149,074 | 0.22 | 289,203 | 2013-04-30 | | Vanguard Institutional Index-Inst Total Stock Market Ind | 138,203 | 0.21 | 281,934 | 2013-03-31 | | iShares Russell Micro Cap (TM) Index Fund | 114,723 | 0.17 | 222,562 | 2013-04-30 |
|
View Transactions for Insiders & Institutional Holders Value shown is computed using the security's price on the report date given. Currency in USD. |
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