For 3D printing stocks, 2015 has not been kind. Over the course of the past 12 months, shares of tiny TheExOne Company have lost 34% of their value. Industry leader Stratasys (NASDAQ:SSYS) is down twice that at 68%. And worst of all is Stratasys' archrival, 3D Systems (NYSE:DDD) whose shares have shed more than 70% of their value.

But one analyst sees hope for the future in 3-D printing -- and at 3D Systems in particular.

Stephens sings a new song
Bright and early Thursday morning, investment banker Stephens, announced that it's upgrading shares of 3D Systems to overweight in response to news that CEO Avi Reichental is stepping down, and will be replaced by current Chief Legal Officer Andrew Johnson.

That may sound strange -- after all, 3D Systems announced Reichental's departure nearly two months ago. But according to Stephens, there's more to the management shakeup than meets the eye. Restructuring efforts spearheaded by Johnson, says the analyst, will "meaningfully improve profitability in FY17." These efforts could permit 3D to beat expectations -- maybe not this coming year, but as early as just two years out. And that's apparently soon enough to encourage Stephens to buy now.

Is Stephens right?
Whether that's a move that you should imitate, however, is a tougher question to answer. After all, Stephens hasn't always been the most reliable source for stock recommendations. Here at Motley Fool CAPS, we've been tracking the performance of Stephens' stock picks since mid-2012, and so far its record has been middling at best: 35% accuracy across 44 recommendations made public, and under-performance of the stock market averaging 1 percentage point per pick.

Hardly encouraging.

Moreover, the only two "tech" stock recommendations we can find for Stephens have both fallen short of the mark:

Company

 

Stephens Says:

CAPS Says:

Stephens' Picks Lagging S&P By:

FLIR Systems

Outperform

***

17 points

Maxwell Technologies

Outperform

***

76 points

Digging into 3D
If there's little to like in Stephens' record in tech, there's arguably even less to like in its latest recommendation. Despite recommending that investors sink their hard-earned money into 3D Systems stock today, even Stephens admits that the most it's hoping to see out of the stock over the next two years is "limited" revenue growth and "flat" gross margins. The analyst places most of its hope in 3D Systems returning to profitability through cost cuts resulting in better operating margins -- but even then, Stephens is only predicting $0.05 in profits this year, and perhaps a dime next year.

Meanwhile, 3D Systems continues to rack up losses and burn cash. According to data from S&P Capital IQ, 3D reported nearly $58 million in losses over the past year, with negative free cash flow approaching $12 million.

Granted, that's better performance than ExOne ($32 million lost on a lower market cap, and $24 million in negative FCF) and Stratasys ($1.2 billion in losses, and $107 million cash-burn). But it's still a pretty poor performance. What's more, even in the best-case scenario of 3D's new CEO succeeding in turning around the business, I'm not convinced 3D is selling at bargain levels just yet.

Consider: Over the five years preceding the stock's recent meltdown, 3D averaged a respectable $30 million in positive free cash flow annually. Analysts who follow the stock on Capital IQ predict long-term profits growth will average just 15% at 3D Systems -- slower than the growth rates at either ExOne or Stratasys.

Now, 15% growth and $30 million in FCF imply for me a fair value of perhaps $450 million on the stock. But in fact, at $1.15 billion in market capitalization, 3D stock sells for nearly three times the price I'd ordinarily want to pay for it.

The upshot for investors
And all that's if 3D Systems succeeds in digging out of the hole it's dug for itself, and returns to average historical levels of cash profitability. If 3D's new interim CEO fails in his efforts to right the ship, 3D could be worth even less.

Long story short, 3D Systems stock has tumbled far over the past year, but when I look at the numbers at 3D Systems today, the stock still looks too expensive. That fact, combined with Stephens' poor record of stock picking -- in the tech sector and elsewhere -- tells me that now is not the time to buy.

Fool contributor Rich Smith does not own shares of, nor is he short, any company named above. You can find him on Motley Fool CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 300 out of more than 75,000 rated members.

The Motley Fool recommends both 3D Systems and Stratasys. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.