Top Insider Trades: SIX VNTV RP OFIX

By Jonathan Moreland, founder of Insider Insights and author of Profit From Legal Insider Trading.

NEW YORK ( TheStreet) -- It is a victory for common sense. Tracking the trading behavior of company executives, directors and large shareholders in the stocks of firms they're registered in as "insiders" has proven to be profitable, according to both academic studies and (more importantly) the experience of professional investors.

Below are lists of the top 10 mainly open-market insider purchases and sales filed at the Securities and Exchange Commission Wednesday, May 15, 2013 as ranked by dollar value. Please note, however, that these are only factual lists, not buy and sell recommendations. Dollar value is only one metric to assess the importance of an insider transaction, and, frankly, often not even the most important metric that determines if an insider transaction is significant.

At, we find new investment ideas just about every day using these and more intricate insider screens to determine where we should focus our subsequent fundamental and technical analysis. And while stocks don't (or shouldn't) move up or down based on insider activity alone, insiders tend to be good indicators of when real stock-moving events like earnings surprises, corporate actions, and new products may be in the offing.

So use these regular Top Insider Trades columns as the initial research tools they are meant to be, and click the links in the tables to analyze a company's or insider's full insider history. Also feel free to contact us with any questions on our proprietary insider data, and how it is best analyzed.
China Biologic (CBPO) Wp X Bio. DIR,BO 3,112,920 62,258,400
Lionbridge (LIOX) Glenhill BO 546,881 1,367,548
Guidance (GUID) RGM BO 67,260 585,440
Orthofix (OFIX) Gero J. DIR 20,000 527,444
Medicinova (MNOV) Izumi Tatsuo DIR 158,730 500,000
Hecla (HL) Baker Phillips PR,CEO,DIR 150,000 478,260
Six Flags (SIX) Luther Jon DIR 5,000 389,608
Marin (MRIN) Lien Christopher CEO,DIR 25,615 246,544
Verastem (VSTM) Clarke John DIR 25,000 243,375
Opko (OPK) Frost Phillip CEO,CB,BO 35,100 243,339
Source: Insider Insights
Vantiv (VNTV) Advent O 24,318,394 557,348,416
YELP (YELP) Anderson Fred DIR,BO 2,006,400 62,288,324
YELP (YELP) Elevation BO 1,003,200 31,144,162
Realpage (RP) Apax DIR 1,250,000 24,062,500
Google (GOOG) Doerr L John DIR 4,602 4,167,190
Crown Castle (CCI) Moreland W PR,CEO,DIR 50,000 3,981,395
Chicago Bridge (CBI) Scorsone Luke VP 65,530 3,761,314
Alexion (ALXN) Bell Leonard CEO,DIR 31,113 3,289,759
Big 5 (BGFV) Stadium DIR,BO 142,131 3,089,380
Keycorp (KEY) Weeden Jeffrey CFO 276,000 2,864,880
Source: Insider Insights

Key to Titles: A=Assistant, AI=Affiliated Investor, AO=Accounting Officer, BD=Business Development, BO=Beneficial Owner, CAO=Chief Accounting Officer, CB=Chairman, CCO=Chief Compliance Officer, CEO=Chief Executive Officer, CFO=Chief Financial Officer, CIO=Chief Information Officer, CO=Compliance Officer, COO=Chief Operating Officer, CT=Controller, CTO=Chief Technology Officer, DIR=Director, EVP=Executive Vice President, F=Founder, FO=Financial Officer, GC=General Counsel, HR=Human Resources, IO=Information Officer, IR=Investor Relations, LO=Legal Officer, MD=Managing Director, O=Officer, OO=Operating Officer, PR=President, PT=Partner, REL=Relative of an insider, SEC=Secretary, SH=Shareholder, SO=Sales Officer, TO=Technology Officer, TR=Treasurer, TT=Trustee, VCB=Vice Chairman, VP=Vice President, X=Ex Officer or other title displayed.