What happened

What went up is coming back down again.

For the past month and a half, investors in space stock Virgin Galactic Holdings (NYSE:SPCE) have been treated to a wild ride. Since Morgan Stanley issued its controversial report in December, predicting that Virgin Galactic shares would triple in value over the course of a year, the stock made a valiant effort at doing just that -- rising from $7.26 a share to $19.72 as of Wednesday's close.

But then reality set in. Virgin Galactic stock slid 3% in Thursday trading, and then the slide accelerated -- closing out Friday trading down another 10%.

Cartoon characters confused by a falling stock chart

Image source: Getty Images.

So what

Virgin Galactic is a great story stock. Arguably the first pure-play space company to become available for purchase on the stock market (at least unless you count space satellite operators such as Intelsat and Iridium), and with a stock-market history less than a year long, Virgin Galactic has little bad news in its past, and potentially lots of good news in its future.

But what about its present?

Presently, there's really not a lot to recommend Virgin Galactic, at least not in the form of numbers you can hang a valuation on. Virgin Galactic has no profit at all, for example -- just losses. Worse, total revenue generated over the past year for this $3.4 billion company total just $4.5 billion. Its price-to-sales ratio is 742.

Now what

Even if you believe that the "space economy" is going to be a thing in the future, it's hard to say at this point whether Virgin Galactic will be part of that future.

For that matter, even if it will be, it's hard to say whether $3.4 billion is a reasonable market value...or too much...or too little. Until Virgin Galactic begins operations, and we get better insight into how profitable it will be (if at all), buying Virgin Galactic stock will feel a lot more like speculating than investing.

And that's a recipe for continued volatility in the stock price, to the upside -- and also to the down.