Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of wind-turbine specialist American Superconductor (Nasdaq: AMSC) were getting blow backwards by gale-force winds today, losing as much as 16% in intraday trading after it filed suit against China's Sinovel.

So what: Writing about American Superconductor's struggles back in July, I said simply: "What a mess." And that was before it sued its former largest customer -- which accounted for roughly three-quarters of its business -- for supposedly stealing its technology. Wait, let me rephrase that. The U.S. company American Superconductor is suing the Chinese company Sinovel over intellectual property. Call me a cynic, but I don't see this ending well for American Superconductor.

Now what: American Superconductor looked to be on a great path -- it had strong topline growth, had tipped into meaningful profitability, and had done it while maintaining a very clean balance sheet. Unfortunately, it appears that the company may turn into a case study in why customer concentration is so dangerous. Because the company has yet to file its annual report for its 2011 fiscal year (which ended in March), let alone its June-quarter report, we don't really know what the company's current, ex-Sinovel financials look like. Except, of course, that revenue will be much lower and there will be a "significant" bottom-line loss. The final chapter certainly isn't in, but I see very little reason to be on the buy side here.

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