Insider buying can be a bullish indicator for a stock and provides another piece of information for investors to weigh when doing investment research. Company executives, board members, and shareholders with stakes exceeding 10% must notify the SEC within two days of their share purchases (and sales) in a Form 4 filing. Each week, I take a look at some of the largest insider purchases in search of investing opportunities with this often positive indicator.

Company Name

Market Cap

No. Shares 
Purchased

Value of Shares 
Purchased

CAPS Rating 
(out of 5)

Valence Technology
(Nasdaq: VLNC)

$184 million

3,759,790

$4.5 million

**
Aon Corp.
 (NYSE: AON)

$11.8 billion

50,000

$2.02 million

**
American Apparel
 (AMEX: APP)

$125 million

1,129,580

$1.67 million

**

Sources:  Barron’s; Motley Fool CAPS.

Valence Technology founder and Chairman Carl Berg reported a purchase of shares of the company in a private placement for $1.20 per share. The battery maker continues to lose money, but business is improving and the company's financials are moving in the right direction. In the company's fiscal second quarter, revenues were up 127% compared to its first quarter, driven by Valence's success selling to commercial fleets. Berg is involved in ventures that collectively own nearly half of the company's shares, and those ventures have continued to invest in more shares as losses have mounted.   

A board member of insurance broker Aon bought shares of the company for members of his family at an average price of $40.47 per share. The timing was great, as the stock has risen nearly 10% in the two weeks following the purchase. Aon shares hit a new 52 week high today.

American Apparel's founder and CEO, Dov Charney, bought shares in the company for $1.48 each, bringing his stake in the business to 57%. American Apparel has been struggling to survive, so Charney's purchase may indicate the company is on the mend.

While Fools should always do their own due diligence, and not blindly follow the insiders, insider buying can point to good places to look for opportunities. To learn more about the stocks The Motley Fool is buying, click here to download a free report, 5 Stocks The Motley Fool Owns-- And You Should Too.