After Mattel posted an 11% drop in it's sales figures on Wall Street yesterday Hasbro's shares also dropped (even though they haddn't posted any figures).

Seeking Alpha reports

Everyone knows or knows someone who knows a “Debbie Downer.” That acquaintance or friend that just won’t let you have a good time. They always seem to pull the good times down and ruin the party for the rest of us.

You can find Debbie Downers in the stock market as well. Today’s example is Mattel (NYSE: MAT). After it reported lower earnings and an 11% drop in sales, it dragged Hasbro (NYSE: HAS) down with it.

The reasoning behind most of these moves is that the pressures hurting one company in a sector should be impacting the competition as well.

But that isn’t always the case.

We can find numerous examples of companies in the same industry with the same pressures that deal with those challenges differently. Southwest Airlines (NYSE: LUV) was able to put up considerable numbers over the past year as its competition suffered greatly. It did this by hedging its oil costs correctly.

Maybe Hasbro hasn’t done the exact same thing as Mattel – and will report similar earnings figures? But who’s to say they did. As smart investors, we cannot assume that is the case. As of this writing, Mattel is down 16% and Hasbro is down 9%.

Let's think about that, a 9% percent drop on no information about their business model. It’s the kind of emotional movement that value investors love.