In light of the uncertain economy, a wide range of insiders have sought to sell company stock, fearing we may eventually have a repeat performance of 2008 when the economy and the stock market headed south. Yet a few bullish insiders are undaunted and have sought to load up on their company stock while others remain skittish. Here are three companies with significant insider buying that recently caught my eye.

1. Titanium Metals (NYSE: TIE)
In a push to make cars, planes, golf clubs, medical devices and many other items stronger and lighter, industrial designers are increasingly turning to titanium. The lustrous metal has the highest strength-to-weight ratio of any element. This may explain why Boeing (NYSE: BA) is using a hefty amount of titanium in its new 787 Dreamliner airplane.

Boeing’s biggest titanium supplier: Titanium Metals. The Dallas, TX-based firm has been around for 6o years, but really only found its footing in the last decade as demand surged. Sales rose from around $400 million in 2003 to $1.2 billion in 2006. Yet the tough economy eventually took its toll, and demand for this high-priced metal started to slump. Titanium Metals’ sales fell below $800 million by 2008 and are only now rebuilding a head of steam. Analysts think sales can top $1 billion this year, and perhaps hit a record $1.25 billion in 2012.

Annual sales growth of 20% is impressive at a time when the broader global economy is barley moving forward. Even more impressive, this is a company with a great deal of operating leverage: profits are expected to grow twice as fast — at least 40% in 2011 and 2012. This bullish outlook explains why company Chairman Harold Simmons has been loading up on shares. Since May 20, he’s picked up 3 million shares at an average price of $17.

As Jonathan Moreland at insiderinsights.com points out, Simmons has a solid track record. He purchased a major block of stock in early 2005, and the stock zoomed ahead 70% that summer.

2. Audiovoxx (Nasdaq: VOXX)
Investors that regularly track the moves of insiders may have missed a seemingly modest stock purchase. Fred Farrar, a director at this consumer electronics vendor, acquired roughly $75,000 worth of stock on the open market in mid-July, right after fiscal first quarter results were released.

Audiovoxx’s quarter was decent enough, with growth in sales and profits coming from a late 2010 acquisition of audio speaker manufacturer Klipsch. The $166 million purchase forced Audiovoxx to part with a considerable amount of cash — at one point in 2010, the company’s cash balance was higher than its market value. Despite the cash drain, this is still very much a balance sheet play, which is perhaps the main reason why Farrar snapped-up shares.

Here’s the math… Audiovoxx is currently valued at around $180 million. Yet the company is owed $119 million from customers, carries another $139 million in inventory and has $40 million in net debt. This adds up to $218 million in net liquid assets –more than the whole value of the company. Lastly, Audiovoxx is generating about $9 million to $10 million in adjusted EBITDA (earnings before interest, taxes, debt and amortization) every quarter, which should only serve to strengthen the balance sheet as time passes. If shares moved up just to reflect those balance sheet factors, then you’d be looking at a 20% upward move. If shares moved up to six times projected EBITDA (valuing the company at $240 million), then you’d be looking at a 33% gain.

3. Rentrak (Nasdaq: RENT)
I highlighted this media analysis firm late last month as a potential second-half rebounder. Just a few days later, insiders took up the cause, collectively purchasing more than 20,000 shares at an average purchase price of around $18. Shares still hold great appeal from where I sit.

Action to Take –> Now that earnings season is underway, expect insider action to build. In tough times like this, insider moves can signal upside for a specific company even when the broader economic outlook is challenging. And this could hold true for any of the three stocks mentioned here.