My daughter is too young to care FTSE 100 index Shares or ISA portfolios. She cares about having a good time at gymnastics, and spends Robux on it Roblox,Getting a hamster for Christmas.

However, I clearly care about her financial future, which is why I opened a Junior Stocks and Shares ISA earlier this year. This is a tax efficient way to help her in the future, as only she will have access to it when she turns 18.

Before that, I will build it on her behalf. This is the FTSE 100 share I keep buying for my Junior ISA.

Please note that tax treatment depends on each client’s individual circumstances and may be subject to change in the future. The content in this article is provided for information purposes only. It is not intended to be, and does not constitute, any form of tax advice. Readers are responsible for conducting their own due diligence and obtaining professional advice before making any investment decisions.

Looking forward to the 30s

My daughter is still a decade away from becoming a young adult. But by 2035, I think advanced technology will be everywhere, like the Internet today. Especially artificial intelligence, self-driving cars, flying taxis, and perhaps even quantum computing and humanoid robots.

Another industry that I expect to become much larger by the mid-2030s is aerospace. Companies like SpaceX and Blue Origin are making significant progress toward making space travel a reality. Against all odds, both pioneered reusable rockets, bringing launch costs down dramatically.

That’s why I keep adding stocks Scottish Real Estate Investment Trust (LSE:SMT) to your ISA. The directors have built a strong group of growing companies that are literally building the future.

Exposure to AI? definitely. The investment fund holds shares Nvidia, Amazona leading chip foundry TSMCAnd data analysis companies Snowflake And data bricks. It has also just acquired a stake in Anthropic, a company “Building the next generation of artificial intelligence“.

Self-driving technology? Also covered. Tesla,nuru, Aurora InnovationAnd Amazon is giving it a lot of exposure here. It also has properties in Gobi Aviationwhich is leading the commercialization of electric flying taxis, and quantum computing startup PsiQuantum.

Oh, and the future space travel industry? Scottish Mortgage’s largest subsidiary is SpaceX, the undisputed global leader in rocketry and space-related innovation.

Up and down

Now, I don’t expect this stock to rise as smoothly and silently as a flying electric taxi. There will be many ups and downs along the way, including a bizarrely brutal sell-off in technology stocks (an inevitable risk with Scottish Mortgage).

The Trust also has stakes in Chinese companies such as ByteDance, owner of TikTok, the electric car giant BYDand Cattle (The world’s largest manufacturer of electric vehicle batteries). But geopolitical tensions between the US and China may escalate in the future, while a global recession and currency fluctuations may negatively impact confidence (mainly owning offshore stocks priced in foreign currencies).

Fortunately, the professional managers at Scottish Mortgage will do all the long-term stock picking on my daughter’s behalf. So you won’t have to worry about any of these fluctuations.

Buy stocks opportunistically

With shares down almost 10% since October, I intend to buy more into a Junior ISA soon. Especially while the trust is trading at a discount of nearly 13% to its underlying net asset value.

However, although I’m bullish on this stock over the long term, and think it’s worth considering today, I wouldn’t be fully invested in it. I will add other stocks to my ISA opportunistically in 2026 and beyond, to build a high-quality mix.

After all, this wallet is for my daughter’s future – and I want it to grow steadily for years to come.