Shares of 3D-printing specialist Stratasys (SSYS) - Get Report have surged about 3% to around $26 since plummeting to a 52-week low of $24.82 on Oct. 2. It would seem investors are betting that the Eden Prairie, Minn.-based company, which reports third-quarter earnings results before the opening bell Wednesday, has put the worst of its struggles behind it. But let's not get carried away.

True, observers of the 3D printing industry have become more upbeat about its growth prospects. But in the case of Stratasys, despite its recent climb, the shares are still down more than 68% in 2015 and almost 80% over the past twelve months. And its peers -- for example, 3D Systems (DDD) - Get Report (down 68% in 2015) and The ExOne Company (XONE) - Get Report (down 33% in 2015) -- haven't fared better.

It would seem the only ones making money on these stocks have been the short sellers. And based on Stratasys' estimates about the quarter that ended in September -- and for fiscal 2015 overall -- avoiding these shares would be a wise move.

Since the start of the quarter, Stratasys' consensus earnings estimates have plummeted 83%, from 48 cents a share to 8 cents a share. This would mark a decline of 86%. The company earned 58 cents a share in the comparable quarter last year, suggesting its underlying business fundamentals are eroding.

Likewise, since the start of the quarter, EPS estimates for the fiscal year ending in December have been lowered 61%, from $1.34 a share to 52 cents a share. This would translate to a year-over-year decline of 74%.

Assuming Stratasys does earn 52 cents a share for fiscal 2015, investors are paying around 50 times forward estimates, or more than three times the P/E ratio of the S&P 500 (SPX) index. In other words, even with the punishment the stock has taken, it's still too expensive and might go lower.

Like its peers, Stratasys' gross margin, which reached 54.7% in the second quarter, is still heading in the wrong direction. It's down 5 percentage points year-over-year. And this is while its operating expenses -- up 23% in the second quarter -- continue to outgrow its revenue (up 2.2%) by a wide margin. Advocates insist the company is building for the future. That's all well and good. But it doesn't make the stock, which is down 50% in the past three years, a worthwhile investment today.

Increased operating expenses, combined with declining profit margins don't equate to value. So, I wouldn't touch this stock with a 10-foot pole ahead of Wednesday's results, especially when management has made no promises to fix its capital strategy.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.