In a victory for common sense, the trading behavior of company executives, directors, and large shareholders in the stocks of firms they're registered "insiders" at have been proven profitable to monitor by both academic studies and (more importantly) the experience of your fellow professional investors.

Below are lists of the top 10 mainly open-market insider purchases and sales filed at the Securities and Exchange Commission Monday, Febraury 25, 2013 as ranked by dollar value.

Please note, however, that these are 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.

In insider purchases, the data storage products and services corporation EMC (NYSE:EMC) bought $6,025,222 worth of stock in VMware (NYSE:VMW). At Mondelez International (NASDAQ:MDLZ), a multinational confectionery, food, and beverage company, Director Frederic Reynolds bought $1,022,200 of company stock. Daniel Akerson, the Chairman and CEO of General Motors (NYSE:GM), bought $662,500 of company stock. William Shea Jr., the President and CEO of Penn Virginia Resource Partners (NYSE:PVR), bought $559,143 in shares. PVR Partners is primarily engaged in the management of coal, natural resource properties, and the gathering and processing of natural gas. 

In insider sales, the Dutch holding company Valcon Acquisition, a Beneficiary Owner of Nielsen (NYSE:NLSN), sold $1,288,299,776 worth of company stock. At oil exploration and production company Kosmos Energy (NYSE:KOS), Director Pincus Warburg sold $491,547,616 while Beneficiary Owner Blackstone Holdings III sold $130,606,752 worth of company stock. Eric Schmidt, the Chairman of Google (NASDAQ:GOOG) sold $64,316,868 worth of company stock. Deer Vi & Co LLC, a Beneficiary Owner and Director of social networking company Yelp (NYSE:YELP), sold $4,856,407 of company stock.

At InsiderInsights.com, 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.

Insider Purchases

#:	Filer Name	Insider Titles	Company Name	Ticker	Trans Type	Dollar Value
1	EMC	BO	VMware	VMW	B	$6,025,222
2	Dondero James D	O	Nexpoint Cr Str Fd	NHF	B	$1,542,502
3	Reynolds Fredric G	DIR	Mondelez Intl	MDLZ	B	$1,022,200
4	Akerson Daniel F	CB,CEO,DIR	General Motors	GM	B	$662,500
5	Shea William H Jr	PR,CEO,DIR	Pvr Partners	PVR	B	$559,143
6	Corcoran Thomas	CB,DIR	Felcor Lodging Tr	FCH	B	$430,403
7	Frost Phillip MD et al	CEO,CB,BO	Opko Health	OPK	B	$316,539
8	Vanwinkle James R	VP,TR	Ferrellgas Partners	FGP	JB*	$116,300
9	Brown Tod D	VP,PR	Ferrellgas Partners	FGP	JB*	$104,670
10	Leposky Mark F	VP,OO	Callaway Golf	ELY	B	$100,425

Source: InsiderInsights.com | Key to Insider Title and Trans Type Codes

Insider Sales

#:	Filer Name	Insider Titles	Company Name	Ticker	Trans Type	Dollar Value
1	Valcon Acquisition	BO	Nielsen	NLSN	JS*	$1,288,299,776
2	Warburg Pincus	DIR,BO	Kosmos Energy	KOS	JS*	$491,547,616
3	Blackstone III	BO	Kosmos Energy	KOS	JS*,S	$130,606,752
4	Schmidt Eric E	CB,DIR	Google	GOOG	AS	$64,316,868
5	Plumeri Joseph J	DIR	Willis	WSH	S	$43,704,016
6	Vassalluzzo Scott J	BO,DIR	Credit Acceptance	CACC	S	$21,973,462
7	Paz George	PR,CB,CEO,DIR	Express Scripts	ESRX	AS	$16,079,146
8	Deer Vi & Co	DIR,BO	YELP	YELP	S	$4,856,407
9	Emmett Dan A	CB,DIR,BO	Douglas Emmett	DEI	AS	$3,312,687
10	Greenspring Assoc	BO	Exacttarget	ET	S	$2,980,144

Source: InsiderInsights.com | Key to Insider Title and Trans Type Codes

Editor's note: Jonathan Moreland is the founder of Insider Insights and author of "Profit From Legal Insider Trading."