You can't keep a good stock down. On the other hand, you can't keep a bad stock up forever.

The Dow Jones Industrial Average (^DJI 0.06%) is up 56 points this afternoon, breaking a three-day streak of negative returns. House Speaker John Boehner finally seems ready to cut a deal on the fiscal cliff, and the markets are breathing a collective sigh of relief.

But the rising tide didn't lift all boats. In particular, fallen technology giant Hewlett-Packard (HPQ -0.25%) failed to follow its Dow peers in a positive trajectory. The stock fell as much as 4% instead, making it the biggest Dow loser today by far.

Hewlett-Packard has been riding a wave of optimism lately -- and for no particularly good reason.

HPQ Chart

HPQ data by YCharts.

In all fairness, HP's drop today is no more substantial than the gains leading up to it. The negative catalyst here is a skeptical research note from Deutsche Bank, which says that breaking HP up into a handful of smaller, nimbler companies might not create any value after all.

Deutsche analyst Chris Whitmore believes that a unified HP comes with synergies and economies of scale that would be hard to replicate with separate consumer and enterprise businesses. If corporate raider Carl Icahn pushes the company into a forced breakup, Whitmore sees him actively destroying shareholder value.

Does Whitmore have his stuff together? I can't find any evidence to the contrary.

The bank has an active "sell" rating on HP with a downright painful $10 price target. Our CAPS system shows that Deutsche has a firm grasp on the computing industry, having scored a solid 414 net points in that sector. Most of that score comes from a long-standing "buy" rating on Apple (AAPL -0.57%), mitigated by an equally long-term but far less successful "buy" on system builder Dell (DELL.DL).

I agree that HP is in dire straits, but I disagree with Whitmore's analysis of a potential breakup. The computing legend would be far better off spinning out the consumer business and doubling down on the enterprise space. Mobile computing has forever changed the face of the IT industry, and HP needs to throw its entire weight behind the enterprise end of the remaining opportunity. Consumer PCs and printers can be left to die as a separate brand or perhaps sold off to some low-cost hardware outfit from China or Taiwan.

So I might not endorse Deutsche Bank's entire thesis on HP, but I do agree with the final outcome: a long and painful decline.