3D printing companies can’t catch a break after a torrid 2013. Now that Stratasys (SSYS) is getting punished for delivering decent earnings, it’s not clear where the bottom lies for 3D printing stocks.

3D printing companies can’t afford anything but beat-and-raise earnings at this point, so when Stratasys said earnings only matched Wall Street estimates, there was ample precedent to expect a selloff in SSYS stock.

We got it … and in the rest of the industry as well.

For 3D Printing Companies, a Good Quarter isn’t Nearly Good Enough

After all, when 3D Systems (DDD) reported quarterly results last week, it only added to the downward pressure on 3D companies this year. 3D Systems’ earnings matched analysts’ estimates, and it came on better-than-expected revenue. DDD even affirmed its outlook.

There’s nothing terrible in any of that.

But delivering so-so news instead of a blowout quarter isn’t an option for richly valued momentum stocks like 3D printing companies — not when so much of the upside depends on speculators chasing higher prices.

DDD stock tumbled on earnings that were fine when fine isn’t nearly good enough. That’s how it goes.

And now it’s Stratasys’ turn.

Stratasys’ Earnings

For the three months ended March 31, Stratasys swung back to the black, with net income of $4.1 million, or 8 cents a share. That compares with a year-ago loss of $15.5 million or 40 cents.

On an adjusted basis, Stratasys earnings came to 40 cents a share, which matched analysts’ average estimate, according to a poll by Thomson Reuters.

SSYS revenue, meanwhile, soared 55% year-over-year to $150.9 million. On an adjusted basis, revenue was $151.2 million, topping Wall Street’s view for sales of $143.3 million.

True, Stratasys forecast a sizable increase in operating expenses this year, driven by investments in sales and marketing. 3D Systems is facing higher costs, too. But that’s not unusual for young, fast-growing operations like 3D printing companies. Stratasys said gross margin expanded significantly thanks to sales of higher-margin products, and its earnings and sales forecasts remain unchanged.

No harm, no foul, right?

Taken at face value, there’s nothing in the SSYS report that should spark a such steep selloff. But then, 3D companies hardly trade at anything like face value.

3D Printing Companies Forced to Feed the Hype

3D printing companies became favorites last year, propelling shares of some of the biggest names to some dizzying heights. Stratasys stock rose 128% in 2013. 3D Systems stock gained more than 160%. ExOne (XONE) saw its shares rise 68% to beat the broader market by almost 40 percentage points.

But as we noted with DDD stock, those kinds of hot runs will stretch the valuation of any stock, and 3D printing companies are no exception.

At 30 times forward earnings, SSYS stock is priced for hot growth … anything that calls that trajectory into question can lead to a beating. That helps explain why SSYS stock is now off more than 35% for the year-to-date, XONE stock is down 45% and DDD stock has fallen 50%.

Expensive, heavily hyped stocks need to feed the excitement with nothing but better-than-expected earnings and outlooks. Anything less is an excuse for speculators to take profits.

The market has been unforgiving of all momentum stocks this year, and 3D printing companies are no exception.

Until that sentiment changes — and 3D printing companies fall to must-buy valuations — it’s too soon to call a bottom in SSYS stock, DDD, XONE or any other names in the sector.

As of this writing, Dan Burrows did not hold a position in any of the aforementioned securities.