The US bull market‘s in full swing, with the S&P 500 recently topping 6,000 for the first time. In my portfolio, two growth stocks have jumped 25% or more within days.

Here, I’ll take a look at each one to see why investors got so excited.

Raising guidance

The first stock is Axon Enterprise (NASDAQ: AXON), which has surged 27% since the law enforcement technology company reported blockbuster Q3 earnings on 7 November.

The share price is now up 783% in five years.

Axon’s business model combines essential hardware (body cameras and Tasers) with subscription software that law enforcement depends on for data and evidence storage. This powerful ecosystem creates recurring revenue and deep customer loyalty.

For Q3, the company reported revenue of $544m, up 32% year on year, while annual recurring revenue grew 36% to $885m. This marked the 11th consecutive quarter of top-line growth above 25%.

Adjusted EBITDA rocketed 54% to $145m, enabling management to raise full-year adjusted EBITDA guidance to $510m (up from a previous estimate of $460m-$475m).

Total future contracted revenue rose 33% to $7.7bn. The firm expects to recognise 15%-25% of this balance over the next 12 months, and the remainder over the following 10 years. As an investor, I like these long-term contracts and the top-line visibility they provide.

AI Era Plan

The company is introducing something called the AI Era Plan. This enables customers to subscribe to an ever-expanding suite of AI-powered capabilities and features. It’s an exciting development.

Plus, I expect law enforcement and government agencies to be well-funded under President Trump. This offers the potential for further contract wins (border control, for example).

One issue here though is a sky-high valuation, with the stock trading at 95 times forward earnings. The company is priced for very impressive future growth, which may not ultimately materialise.

Another risk is the potential for a serious data breach. Axon now has more than 2bn evidence files loaded into its cloud-based management system (Axon Evidence), totalling more than 400 petabytes of data.

It’s hard not to be bullish long term. But given the very high valuation here, I’m wary about investing in the stock at present. If I wasn’t a shareholder, I’d consider waiting for dips to build out my position over time.

E-commerce

The second surging stock is Shopify (NYSE: SHOP). Shares of the e-commerce enabler surged 25% yesterday (12 November) after a marvellous Q3.

Revenue increased 26% to just under $2.2bn, while gross merchandise volume (the total value of goods sold through the platform) was up 24% to $69.7bn.

Shopify’s free cash flow margin reached 19%, up from 16% the year before. And it sees Q4 revenue rising 25%-29%, far surpassing Wall Street’s prior forecast for 22.8% growth.

One risk is competition from Amazon and Salesforce‘s Commerce Cloud. Both could steal market share.

However, this is a massive global market, with Shopify powering millions of online businesses, including Mattel and Gymshark. It makes money from subscription fees and merchant solutions, growing alongside its customers. So it was encouraging to see established enterprises like Reebok join the platform during the quarter.

Again, Shopify stock is expensive (it always is). But that hasn’t stopped it rising 248% in five years. Still, if I wasn’t already a shareholder, I’d be mindful of the premium valuation here.