With the advent and explosion of online financial content as well as sites dedicated to tracking insider activity like Insider Monkey, it is easier than ever to be aware of what insiders are buying and selling at their companies. It is something I peruse at least once a week to come up with new investment ideas to research further.

Here are three small cap stocks that look attractive at current levels and also have had recent insider buying. All are currently under $5.00 a share.

Let’s start with Ladenburg Thalmann Financial Services (NYSE: LTS). Ladenburg is one of the longest operating brokerage firms around as well one of the oldest members of the New York Stock Exchange. The company has over 4,000 financial advisors and  helps firms raise capital via debt and equity offerings.

Noted billionaire and biotech entrepreneur Dr. Phillip Frost owns a decent chunk of the firm. The company has a market capitalization of just over $400 million and a stock price just below $2.50 a share. Dr. Frost and several other directors have been frequent buyers of the shares over the past few months.

Ladenburg continues to buy up smaller firms and should post revenue growth north of 25% this year. Currently, the company is posting small losses. However, when you compare it to other brokerage firms like Raymond James (NYSE: RJF), based on price to sales or to the valuation placed on assets under management, Ladenburg is deeply undervalued.

Pernix Therapeutics Holdings (NASDAQ: PTX) is next up on our interesting small cap stocks insiders are buying. This small biopharma concern has three key drugs on the market: Treximet, Silenor and the recently acquired Zohydro which treat pain and sleep disorders. The stock has been under pressure as the company lowered guidance during its last quarterly earnings call mainly as the result of the integration of the recent purchase of Zohydro, which came with its own sales force. The stock currently goes for just over $4.00 a share and the company has a market capitalization of approximately $250 million.

The dip is a buying opportunity based on recent insider activity as three directors bought additional shares in the company in August. Analysts also like the stock overall. The median price target by the four analysts that cover the stock is $10.50 a share. Sales are tracking to 40% to 50% year-over-year growth this fiscal year. Another 30% increase is projected for FY2016. After posting small losses over the past couple of years, Pernix should earn 50 cents a share in 2016 as it integrates its new Zohyrdro business. This makes the stock very cheap on a forward earnings basis.

Next up is the most speculative high risk/high reward of the companies profiled in this article. It is a small biotech concern called Immune Pharmaceuticals (NASDAQ: IMNP). The company has a market capitalization of just $50 million and a stock price that hovers just above $1.50 a share. Three directors bought stock early in September.

The company is a clinical-stage biopharmaceutical company developing and commercializing targeted therapeutics for the treatment of inflammatory diseases and cancer. The company has multiple “shots on goal” and recently secured funding to run operations and trials through 2016. The company’s main drug candidate is bertilimumab which is currently being tested in Phase 2 clinical trials for bullous pemphigoid and ulcerative colitis. With the extra funding, the company could expand testing of bertilimumab into nonalcoholic steatohepatitis commonly known by the acronym NASH.

The company is also developing a topical nano-formulation of cyclosporine A, which it recently licensed for the treatment of atopic dermatitis and psoriasis. Finally, Immune is developing something called NanomAbs which is a targeted nanoparticle conjugate used for the treatment of cancer. Three analyst firms cover the company. All have Buy ratings and $6.00 a share price targets on Immune Pharmaceuticals.

Like every biotech concern without approved products on the market, the stock is highly dependent on trial results. However, successful results could trigger a massive rally in the shares if one goes by analyst views. Insiders seem to be buying into the story looking at recent purchases.

Finding biotech stocks with recent insider purchases is one of the criteria I look for in finding biotech takeover targets. In my newly released video I reveal the 5 other criteria I look for that help me Consistently Discover Biotech Takeover Targets.