What: Shares of Constellium NV (NYSE:CSTM) fell 25% today after the company reported second-quarter earnings.

So what: Quarterly revenue jumped 49% to $1.52 billion and adjusted loss per share was $0.68. Revenue was above the $1.38 billion analysts expected, but the loss was a surprise given analysts' expectation of a $0.21-per-share profit.  

Now what: One of the more concerning statements from management today was that the performance for Muscle Shoals were expected to be down in the second half of the year because it benefited from a competitor outage in the first half. But even the first half of the year wasn't a blowout, because aluminum prices fell by nearly two-thirds then. Given the weakness and the loss reported for the second quarter, I don't see much of a reason to get bullish on this stock today. Management needs to prove long-term profitability before I would jump in, and that could take years in today's competitive environment.