Insiders Buy Shares at Achillion Pharmaceuticals, ChemoCentryx, and Walter Energy

Welcome to our daily roundup of top insider trades. Here's a look at the most significant inside purchases recently filed with the SEC.

Notable Purchases:

Boston-based investment adviser Ra Capital Management bought 1,186,007 shares of biopharmaceutical company Achillion Pharmaceuticals (NASDAQ:ACHN) for $2,902,711. Achillion focuses on the discovery, development, and commercialization of treatments for infectious diseases. This purchase was filed with the SEC on the same day -- Monday, September 30 -- as a major sale of company stock by QVT Associates GP LLC.

The private equity firm BVF Partners LP bought 336,225 shares of biopharmaceutical company ChemoCentryx (NASDAQ:CCXI) for $1,676,808. ChemoCentryx develops oral-administered therapeutics for the treatment of autoimmune diseases, inflammatory diseases, and cancer.

The investment firm RGM Capital bought 119,460 shares of scientific informatics company Accelrys (NASDAQ:ACCL) for $1,111,992.

David Beatty, a director at metallurgical coals producer and exporter Walter Energy (NYSE:WLT), bought 10,000 shares of company stock for $168,700.

For more insider trades, see the charts below.

**Insider Purchases**
#:	Filer Name	Insider Titles	Company Name	Ticker	Trans Type	Dollar Value
1	Srinivasan Mallika	DIR	AGCO	AGCO	AB	$3,625,176
2	Ra Capital Mgt	BO	Achillion Pharm	ACHN	B	$2,902,711
3	Bvf Partners LP	BO	Chemocentryx	CCXI	B	$1,676,808
4	RGM Capital	BO	Accelrys	ACCL	B	$1,111,992
5	Acp Iv	BO	Aerie Pharm	AERI	JB*	$1,100,000
6	Baker Robert N	DIR	Cardinal Ethanol	CRDE	JB*	$650,000
7	Marubeni	DIR,BO	Aircastle	AYR	B	$568,710
8	Frost Phillip Md	CEO,CB,BO	Opko Health	OPK	B	$345,598
9	Anido Vicente Jr	CEO,DIR	Aerie Pharm	AERI	JB*	$280,000
10	Beatty David R	DIR	Walter Energy	WLT	B	$168,700

**Insider Sales**
#:	Filer Name	Insider Titles	Company Name	Ticker	Trans Type	Dollar Value
1	Gates William	DIR	Microsoft	MSFT	AS	$142,506,400
2	Carlyle	BO	Commscope	COMM	JS*	$109,326,912
3	Roche Collin E	DIR,BO	Privatebancorp	PVTB	JS*	$49,000,000
4	Huntsman James	PR	Huntsman	HUN	S	$6,924,840
5	Farrington Deborah	DIR	Netsuite	N	S	$2,938,957
6	Drucker Charles	CEO,DIR	Vantiv	VNTV	AS	$2,722,920
7	Miau Matthew	DIR	Synnex	SNX	S	$2,460,587
8	Hawken Jeffrey C	VP,COO	Kilroy Realty	KRC	S	$2,146,000
9	Thaler Warren S	DIR	Align Technology	ALGN	S	$1,993,553
10	Stevens Michael J	VP,CFO	Whiting Petroleum	WLL	S	$1,567,923

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

An important note from Jonathan Moreland, founder of Insider Insights:

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

Please note, however, that the lists above are strictly factual; they are 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 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.

Jonathan Moreland is also the author of "Profit From Legal Insider Trading."