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 GT Advanced Technologies (OTC:GTATQ) have lost a whopping 89% of their value Monday after the crystal manufacturing specialist filed for bankruptcy protection in New Hampshire.

So what: GT's Chapter 11 filing became public knowledge shortly after the start of the trading day, and its shares were temporarily halted. Once trading resumed, GT took a predictable plunge, but it's yet to be completely wiped out -- the company's market cap continues to hover around $100 million as of this writing -- because the company has noted $85 million in cash reserves and has pledged to conduct business as usual while seeking out debtor-in-possession financing. CEO Tom Guitierrez told the public, "Today's filing does not mean we are going out of business; rather, it provides us with the opportunity to continue to execute our business plan on a stronger footing, maintain operations of our diversified business, and improve our balance sheet."

Now what: GT will provide more information on its restructuring process as soon as possible, but even so, it's unlikely that investors will find any positives in the stock today. Companies have emerged from bankruptcy to produce strong gains before, but the process is long and arduous. There is no reason to touch this toxic stock until more information is available.