Another week, another new high for Shopify (NYSE:SHOP). One of the market's biggest winners keeps inching higher, notching its latest all-time high on Thursday before opening at yet another new high-water mark on Friday morning. Shopify stock has risen 46% so far this year, up a blazing 250% since the start of last year.

There was no company-specific news fueling this week's push through the ceiling. Shopify did introduce a new chief financial officer and chief marketing officer on Monday, but these aren't necessarily stock-moving events. Momentum is simply lifting the shares higher, something that comes with the territory when you string together enough blowout quarters the way Shopify has during its meteoric run.

A facebook page displaying different outdoor apparel using Shopify's platform.

Image source: Shopify.

Riding the e-commerce wave

Shopify empowers entrepreneurs with the tools to easily set up online stores, and the dinner bell gets louder with every passing quarter. Shopify closed out 2017 with more than 600,000 merchants on its platform, and these digital storefronts aren't collecting dust. Shopify generated a record $9.1 billion in gross merchandise volume in its latest quarter.

There aren't too many e-commerce companies growing as quickly as Shopify. Revenue rose 71% in the fourth quarter and 73% for all of 2017. Shopify generates revenue through subscriptions to its platform as well as merchant solutions, and those segments rose 67% and 74% in the fourth quarter, respectively. Put another way, Shopify is hitting on all cylinders right now.

Profitability has been a knock on Shopify, but it's starting to make headway on that front. It has posted back-to-back quarters of earnings on an adjusted basis, and Wall Street pros see profits expanding as Shopify basks in the merits of its scalable model. Several analysts boosted their price targets following last month's well-received financial report, and the stock has already barreled through a couple of the updated goals.

Valuation is a concern, but one can argue that worrywarts had those same fears with the stock at much lower levels. The stock has more than tripled since the start of last year and soared better than sixfold if we draw the starting line a year earlier. It may not be fair to value Shopify based on its earnings multiple at this point in its growth cycle, but even if we focus on the top line, Shopify is fetching more than 20 times its trailing revenue. The stock is a popular short, but that also makes it that much easier to keep moving higher when strong quarterly results and new deals are announced.

Shopify isn't cheap, but asking if one of the market's hottest tech stocks over the past two years has finally peaked underestimates the power of momentum. Growth would have to decelerate sharply and Shopify would have to start coming up short with its quarterly updates for the tide to turn the other way. Skeptics will question the size of the opportunity here given Shopify's total addressable market and even one prolific boo bird has called the company's aggressive marketing into question. Shopify has managed to climb the wall of worry before, and it's hard to bet against a company that's hitting new highs again this morning.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.