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 gold miner Golden Star (AMEX: GSS) fell 10% today after the company announced disappointing production from two mines.

So what: The Bogoso/Prestea Mine is now expected to produce 39,000 ounces of gold, down from a previous estimate of 43,000. Wassa Mine also will not live up to expectations, producing about 35,000 ounces versus previous guidance of 40,000 ounces.

Now what: The move looks remarkably logical from a market that can often be irrational. Guidance is down about 10% and therefore the stock is down 10%. The lower milled grade at Bogoso/Prestea is a bit of a concern, but most of the disappointment was related to equipment downtime. I don't see a great need to adjust your investment thesis today, but it might be a good time to buy if you were looking to build a position.

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.