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 Monday, May 13, 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.
Resolute (REN) Spo BO 6,273,000 50,439,310
Spectrum (SPB) Harbinger BO 47,000 2,700,095
Murphy Oil (MUR) Deming C DIR 30,000 1,915,948
Vocus (VOCS) Okumus OV BO 113,274 940,897
Teche (TSH) Teche Bank BO 17,261 708,564
Walter (WLT) Tokarz Michael DIR 25,000 475,000
Alleghany (Y) Sennott John VP 1,000 393,938
Cardiovascular (CSII) Nelson Glen DIR 18,393 333,139
Polyone (POL) Diemer Richard VP,CFO 10,000 241,709
Axiall (AXLL) Mansfield W DIR 5,000 231,800
Source: Insider Insights
Hertz (HTZ) C Dubilier & Rice Fd BO 16,649,571 411,494,144
Epl (EPL) Wexford BO 383,206 12,954,665
YELP (YELP) Deer Vi DIR,BO 246,300 7,614,674
Scotts (SMG) Hagedorn BO 148,212 7,074,888
Zillow (Z) Barton Richard CB,DIR,BO 116,046 6,340,071
Humana (HUM) McCallister Michael DIR 65,000 5,051,833
MSC (MSM) Jacobson Mitchell DIR,BO 45,000 3,680,458
Gartner (IT) Hall Eugene CEO,DIR 55,807 3,216,716
Realty (O) Malino Gary PR,COO 61,132 3,194,758
Lpl (LPLA) Putnam James DIR 70,000 2,520,000
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.

Jonathan Moreland is the founder of, which produces a weekly newsletter and offers professional screening and alerting tools to analyze a proprietary, real-time insider data feed. He is also the principal of Insider Asset Management, a registered investment advisor in New York. Mr. Moreland has been analyzing insider data professionally for two decades and has been a contributor to since 2001. A fundamental analyst with an MBA in finance, Mr. Moreland long ago identified insider data as an excellent first screen to determine where to focus his research efforts. He is quoted frequently in the media for his insider analysis and stock recommendations stemming from it. He is also author of Profit From Legal Insider Trading.

Under no circumstances does the information in this column represent a recommendation to buy or sell stocks. While he cannot provide investment advice or recommendations, Moreland appreciates your feedback; click here to send him an email.