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 iron ore royalty trust Mesabi Trust (NYSE: MSB) fell as much as 10% on above-average volume.

So what: Shares of Mesabi continue to experience unusually big swings of late on extraordinarily high volume. The stock seemed to be recovering nicely from last Thursday's 16% plunge, but today's double-digit loss -- already coming on more than 2.5 times the average volume -- erases the gains made over the past week.

Now what: With still no obvious news out, today's weakness looks like yet another opportunity to pounce. While Mesabi is up more than 230% over the past year, it sports a tantalizing dividend yield of about 8%. As long as you're able to handle the extreme volatility, Mesabi seems like a total-return bet worth considering.

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