Insider buying can be a bullish indicator for a stock and provides another piece of information for investors to weigh when doing stock research. I also like to look at insider buying for new ideas for my portfolio.

Company executives, board members, and shareholders with stakes exceeding 10% must notify the Securities and Exchange Commission within two days of their share purchases (and sales) in a Form 4 filing. Here are some of the biggest purchases over the last week that caught my eye.

Company

Market Cap

No. Shares Purchased

Value of Shares Purchased

CAPS Rating (out of 5)

Kratos Defense & Security Solutions (Nasdaq: KTOS)

$175 million

100,000

$1.02 million

*****

Saul Centers

(NYSE: BFS)

$801

million

11,500

$499,000

*

MSCI (Nasdaq: MSCI)

$4.26 billion

10,000

$338,000

**

Sources: Barron's, Yahoo! Finance, and Motley Fool CAPS.

Kratos Defense & Security specializes in cybersecurity and engineering and IT services for weapons systems. Analysts believe that these high-tech defense programs will see increased spending, even if larger defense programs supported by giants such as General Dynamics (NYSE: GD) and Lockheed Martin (NYSE: LMT) see spending cuts. But since so much of the company's work is classified, it is difficult to predict how the company will fare.

To further enhance its position in the security business, Kratos is acquiring Henry Brothers Electronics, a competing security firm. The company's shares have fallen almost 30% since April, making them more attractive for investors seeking value. Board member Bandel Carano reported that the venture capital firm he manages, Oak Investment Partners, bought $1 million of the stock last week at $10.20 per share on behalf of various funds Oak runs.

Like Kratos Defense & Security, Saul Centers benefits from government spending, though in its case indirectly. The REIT owns shopping centers and office buildings in the Washington, D.C., metro area. The company's chairman and CEO, B.F. Saul, has been buying shares of the company throughout the year, in some cases for family member trusts. The REIT is trading near its 52-week high and currently yields 3.3%.

MSCI, best known for its international market indexes, saw insider buying from board member George Siguler. Siguler bought 10,000 shares a few days after the company announced disappointing earnings because of restructuring charges related to its acquisitions of RiskMetrics and Measurisk.

These companies are not specific recommendations, but may be worth looking at more closely. For more on the companies and industries mentioned, check out:

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Fool contributor April Taylor does not own shares in the companies mentioned. General Dynamics is a Motley Fool Inside Value pick. Try any of our Foolish newsletter services free for 30 days. The Motley Fool has a disclosure policy.