Investors are notoriously fickle, and notoriously wrong. So it's always tricky to read too much into any spikes in share prices.

But once in awhile investor sentiment is right, and when an entire sector gets a boost, it's enough of a trend that it's worth pointing out.

Over the past month -- a period that, of course, has been horrible for world markets -- shares of Chilean salmon companies have leaped sharply, with Multiexport (the orange-colored lines in the graphs below) leading the pack at a more than 42 percent jump.

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