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 Wednesday, February 27, 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, Berkshire Hathaway (NYSE:BRK.B), a beneficial owner of dialysis and kidney services company DaVita HealthCare (NYSE:DVA), bought $24,696,932 worth of company stock. The data storage products and services corporation EMC (NYSE:EMC) bought $4,998,104 worth of stock in cloud infrastructure and virtualization company VMware (NYSE:VMW). Phillip Frost, CEO and Chairman of pharmaceutical and diagnostics company Opko Health (NYSE:OPK), bought $454,329 worth of company stock.. At electronic control device (a.k.a. taser) manufacturer TASER International (NASDAQ:TASR), Director Hadi Partovi bought $354,925 worth of company stock.

In insider sales, Brown & Williamson, a beneficiary owner of tobacco company Reynolds American (NYSE:RAI), sold $29,733,528 worth of company stock. Reynolds American was created in 2004 when Brown & Williamson, then a controversial company due to claims against it of adding addictive chemicals to cigarettes, merged with R.J. Reynolds. At online vacation rental company HomeAway (NASDAQ:AWAY), partner and beneficiary owner TCV VI L P sold $18,098,688 worth of company stock. Louis Camilleri, Chairman and CEO of Philip Morris International (NYSE:PM), sold $5,123,250 worth 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	Berkshire Hathaway	BO	DaVita HealthCare	DVA	B	$24,696,932
2	EMC	BO	VMware	VMW	B	$4,998,104
3	Rollins James D	CEO,DIR	Bancorpsouth	BXS	B	$834,417
4	Frost Phillip MD	CEO,CB,BO	Opko Health	OPK	B	$454,329
5	Partovi Hadi	DIR	TASER Intl	TASR	B	$354,925
6	Hughes D Michael	DIR	Oceaneering Intl	OII	B	$312,683
7	Anderson Steven R	DIR	Sunoco Logistics	SXL	B	$303,810
8	Weisz Stephen P	PR,CEO,DIR	Marriott Vacations	VAC	B	$302,325
9	Blanchard Paul Jr	VP,COO	Panhandle Oil	PHX	JB*,B	$135,050
10	Heckaman Alton D	VP,CFO	Swift Energy	SFY	B	$131,000

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	Brown & Williamson	BO	Reynolds Amer	RAI	S	$29,733,528
2	Tcv Vi	PT,BO	HomeAway	AWAY	S	$18,098,688
3	Index Ventures Gr	BO	Rpx	RPXC	S	$13,209,000
4	Frazier Laura	BO	Brown Forman	BFB	S	$8,552,339
5	Camilleri Louis C	CB,CEO,DIR	Philip Morris Intl	PM	S	$5,123,250
6	Tornier Alain	DIR	Tornier	TRNX	S	$4,813,636
7	Renfro Larry C	VP,CEO	UnitedHealth	UNH	S	$4,448,436
8	Wallace Timothy R	CB,CEO,PR	Trinity Industries	TRN	S	$4,185,636
9	Macquarie Infra Mgt	DIR,BO	Macquarie Infra	MIC	S	$3,143,330
10	Ferguson John D	CB,DIR	Corrections Corp	CXW	S	$3,091,718

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."