It's too soon to say, despite the fact that the rule is part of a two-year-old law.
The Volcker Rule bans deposit-taking banks from making speculative bets. But it allows banks to make investments to hedge risks.
Whether the JPMorgan trade counts as a hedge gone horribly wrong (and therefore kosher under Volcker), or as a speculative bet (and therefore prohibited) depends in part on the details of how the rule is written.
And those details have yet to be finalized.
The rule was included in the Dodd-Frank act, the big financial-reform bill that Congress passed in 2010. It was a few pages long in the statute.
The proposed details of how the rule will be implemented run to hundreds of pages. Five different regulatory agencies are collaborating. And the banks are weighing in with their own, extensive comments.
This long, slow implementation isn't unusual at all. It's entirely typical. Dodd-Frank called for hundreds of new rules; only 27 percent of those have been finalized, according to this recent report (PDF).
The details of the Volcker Rule are likely to be finalized later this year. But the regulators recently said banks will have until 2014 to comply fully with the final rule — four years after Dodd-Frank was passed, and six years after the financial crisis.