What happened

Shares of mobile payment company Square Inc (SQ 0.51%) have jumped 86.5% so far in 2018, according to data provided by S&P Global Market Intelligence, as operating conditions continue to improve. If the company's growth keeps up, the sky is the limit for the stock. 

So what 

The stock really started to perk up after Square reported first-quarter results. Adjusted revenue jumped 51% from a year ago to $307 million, adjusted EBITDA rose 33% to $36 million, and net loss nearly doubled to $24 million. That loss may sound bad, but spending on research and development and sales to grow the business is what's driving it, and that's a good idea right now

Square reader on the counter at a bakery.

Image source: Square.

What's encouraging from an investment standpoint is that EBITDA is rising, indicating that money is starting to flow to the bottom line for Square. I also like that big sellers are beginning to use the platform. Management said that 20% of annualized gross payment volume was from sellers with over $500,000 of transactions, up from 16% a year ago. If Square can move beyond food trucks and salons to bigger retailers, it would be great for the sustainability of the business. 

Now what

Since Square isn't profitable, it's tough to call the stock cheap by any traditional metrics today. But the company is growing at a rapid clip and upending the traditional payments business in the process. As Square expands its offerings to include more services -- from scheduling to capital -- I think it could be one of the most disruptive payment processing companies on the market. This is a business with a bright future still ahead.