3 booming growth shares in the Scottish Mortgage portfolio

Shares of Scottish Mortgage Investment Trust (LSE: SMT) are up around 25% over the past year. That’s undoubtedly impressive.

Underneath though, at the portfolio level, some of the trust’s holdings are absolutely rocketing. Here, I want to highlight three of them to assess whether any are worth considering.

Hitting $4trn

Let’s start with the most high-profile, which is AI chipmaking juggernaut Nvidia (NASDAQ: NVDA). Shares are up 83% since the start of April, giving the company a mind-bending market cap of $4.22trn.

For context, that’s nearly 20 times the size of HSBC, the UK’s largest listed firm.

The news that recently sent Nvidia to a $4trn valuation — the first company to ever reach this milestone — was related to China. Namely, the US is allowing Nvidia to once again export its modified H20 AI chips to China. This was part of trade negotiations over rare earth metals.

According to Reuters, internet giants Tencent and TikTok-owner ByteDance are already lining up to get their hands on these chips. I doubt they’ll be alone in the queue. So this is great news for Nvidia shareholders. 

The company remains at the epicentre of the AI boom. But there are risks, which Scottish Mortgage manager Tom Slater recently highlighted: “If AI is to become truly transformative, it also needs to become ubiquitous and that points to commoditisation. A world built on $70,000 chips and 60% margins isn’t likely to endure.”

Here, Slater is casting doubt on whether Nvidia can sustain its pricing power as the AI revolution matures. In response, the trust has been trimming its Nvidia stake, having made over 100 times its money since 2016.

Despite this, the stock remained a top 10 position at the end of June.

Two other high-fliers

Elsewhere, Joby Aviation (NYSE: JOBY) has taken to the skies, fittingly for a flying air taxi firm. It’s gone from $5 to $17 since April — a gain of 240%.

The stock has been buoyed by news that Joby has successfully carried out trials of its aircraft in Dubai, ahead of a planned launch in early 2026. It then intends to expand its air taxi service globally, from the US and UK to Japan.

Earlier this week, Joby also announced that it will double its manufacturing capacity, allowing it to produce up to 24 aircraft per year (nearly one every other week).

Finally, global gaming platform Roblox is on fire. Shares have more than doubled year to date.

The company recently launched a new intellectual property licensing platform, enabling brands like Netflix, Sega, and Lionsgate to integrate their characters and worlds into the Roblox ecosystem. 

Hefty valuations

The strong performance of such stocks obviously bodes well for Scottish Mortgage (it reports the current period in November). But are any of them still worth a look?

Unfortunately, I’m not convinced they are, despite me holding all three. Joby has a $14.5bn market cap but no revenue (yet), which makes it highly speculative. And if Roblox disappoints with its revenue growth, the market could punish such missteps very severely.

For exposure to these stocks (and around 95 others), I think investors could consider Scottish Mortgage shares.

While there’s a risk the 10% discount to net asset value could widen further, the portfolio of growth companies looks incredibly strong today.