(Bloomberg) -- When Petrobas sold 100-year bonds in June, the move was largely seen as a sign the corruption-tainted oil producer had put the worst of its problems behind it.

For investors like Pimco, Fidelity and Capital Group -- the three biggest holders of the securities -- that turned out to be a costly miscalculation. Since the $2.5 billion offering, the bonds have tumbled 15 %. That’s four times the average loss for emerging-market company debt.

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