What: Shares of manufacturer AK Steel Holding Corporation (NYSE:AKS) jumped as much as 12% today after the company reported earnings that were better than expected.

So what: AK Steel's second-quarter net sales jumped 10.3% to $1.69 billion on a 30% increase in shipments. Falling selling prices for steel was a big drag on revenue.  

On the bottom line, net loss grew nearly fourfold to $64 million, or $0.36 per share, but that was a penny ahead of Wall Street's estimates.

On top of earnings, AK Steel said that it has joined a trade case against eight countries for antidumping and countervailing duties on cold-rolled steel.

Now what: The steel industry is in dire straits right now, as cheap imports eat away at sales prices. That has resulted in both the growing loss and the move to ask for tariffs from the government. I think that's a bad sign for AK Steel, and until the company can prove it can make money long term, investors should be cautious. The upside may look attractive, but beware of catching a falling knife in these shares.