By David Sterman

NEW YORK ( TheStreet) -- Billionaire investors George Soros and Carl Icahn helped push up the shares of Exar ( EXAR) and Hain Celestial ( HAIN), respectively, last month.

Above are the most significant acquisitions of stock.

Exar rose more than 3% in September after the chipmaker's stock fell to a low for the year at the end of August. Hain climbed 2.5% last month, bringing the year's gains to 41% at the health foods and tea company.

As October begins, I took a look at the most significant purchases of company insiders. I focused on the 26 companies that saw at least $1 million in insider buying this past month. Here's a breakdown of three stocks.

Hain Celestial: As we've seen with the case of Motorola ( MOT), hedge fund investor Carl Icahn never makes a small bet. (Read Carl Icahn's Favorite Stock.)

Motorola is Icahn's favorite stock, but Hain Celestial may be a close second. Icahn has been steadily buying shares of this health foods and tea maker on the open market, and just acquired another $30 million worth in September. Curiously, he's been buying shares even as they have been steadily rising. Insider buying is more often associated with beaten-down stocks.

This is an unusual growth story. The company has a long history of acquisitions, helping to boost sales 10% to 20% most years. But in the absence of acquisitions, organic growth has been very small. And investors tend to avoid growth-led acquisition strategies because they don't always boost the bottom line. Indeed, Hain Celestial's earnings per share have hovered between $0.50 and $1 for most of the past eight years.

Recent trends have become a bit more favorable. Per-share profits are likely to rise more than 25% to around $1.30 this year, but in the absence of more deals, profit growth is expected to slink back to single-digits next year.

From Icahn's perspective, near-term profits may not be the litmus test. Instead, he likely sees an asset that is being built that would ultimately make a nice fit for a larger food maker such as Kraft ( KFT), Nestle or Conagra ( CAG). But that's a risky strategy. Who knows if such a deal will materialize? Hain Celestial looks only modestly undervalued by traditional investment metrics, so anyone looking to ride along with Icahn may be counting on him to do some cage-rattling to unlock shareholder value, as he has done with Motorola.

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