How I could make £1 million investing in an ISA

This writer sets out a realistic strategy and timeframe for getting to a seven-figure ISA portfolio by investing in the stock market.

| More on:

The content of this article was relevant at the time of publishing. Circumstances change continuously and caution should therefore be exercised when relying upon any content contained within this article.

British pound data

Image source: Getty Images

When investing, your capital is at risk. The value of your investments can go down as well as up and you may get back less than you put in.

Read More

The content of this article is provided for information purposes only and is not intended to be, nor does it constitute, any form of personal advice. Investments in a currency other than sterling are exposed to currency exchange risk. Currency exchange rates are constantly changing, which may affect the value of the investment in sterling terms. You could lose money in sterling even if the stock price rises in the currency of origin. Stocks listed on overseas exchanges may be subject to additional dealing and exchange rate charges, and may have other tax implications, and may not provide the same, or any, regulatory protection as in the UK.

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More.

Reaching a million pounds in a Stocks and Shares ISA isn’t as far-fetched as it sounds. According to the latest data available, there were nearly 5,000 ISA millionaires in the UK!

However, those figures were from over 18 months ago. Here’s what the stock market has done since then:

  • FTSE All-World Index: +33%
  • S&P 500: +48%
  • Nasdaq: +64%
  • FTSE 100 +8%
  • FTSE 250: +12%

These returns don’t even include dividends. Therefore, I assume there’ll be well over 5,000 investors with a seven-figure portfolio right now. We’ll know for sure when the next set of figures is released.

Should you invest £1,000 in National Grid right now?

When investing expert Mark Rogers has a stock tip, it can pay to listen. After all, the flagship Motley Fool Share Advisor newsletter he has run for nearly a decade has provided thousands of paying members with top stock recommendations from the UK and US markets. And right now, Mark thinks there are 6 standout stocks that investors should consider buying. Want to see if National Grid made the list?

See the 6 stocks

Here, I’ll outline how I aim to one day join this growing ISA millionaire club by investing quite modest sums.

Active investing

My first goal is to try and max out the annual ISA allowance, which currently stands at £20,000. This works out at approximately £1,666 a month or £384 a week.

Next, I aim to beat the market by picking individual stocks (active investing). My portfolio is globally diversified, including many UK and US shares, so I think the FTSE All-World Index is a good benchmark.

It’s comprised of about 3,645 large and mid-sized company stocks in developed and emerging markets.

The average annual return of this index is around 10.3%. I’m targeting a return slightly above this over time (roughly 12%).

A potential hidden gem

One under-the-radar stock I’ve been considering for my portfolio is Novocure (NASDAQ: NVCR). This is a global oncology company that has pioneered Tumour Treating Fields (TTFields) therapy.

This involves the use of electric fields to disrupt cancer cell division, while sparing healthy cells. Its flagship product is Optune, a scalp-worn, portable device approved for an aggressive form of brain cancer.

In Q3, the firm’s revenue grew 22% year on year to $155m. However, its net loss was $30.6m, due to $51.9m in research, development, and clinical studies expenses.

Though I expect the firm to reach profitability, these losses add risk, despite it also having $960m in cash.

On 2 December, the firm announced that its TTFields therapy extended the lives of patients with a form of advanced pancreatic cancer when combined with chemotherapy.

This was Novocure’s third positive Phase 3 clinical trial in the last two years. And upon this news, the stock exploded nearly 50% higher. However, it still remains 87% below its mid-2021 record.

Novocure will probably file for regulatory approval of this new cancer product in 2025, with its Chinese partner, Zai Lab, doing likewise in China.

From today’s modest $2.9bn market cap, I think the stock could outperform long term. I’m seriously considering it.

Created with Highcharts 11.4.3NovoCure PriceZoom1M3M6MYTD1Y5Y10YALL7 Dec 20197 Dec 2024Zoom ▾Jan '20Jul '20Jan '21Jul '21Jan '22Jul '22Jan '23Jul '23Jan '24Jul '242020202020212021202220222023202320242024www.fool.co.uk

Getting to £1m

So, I have my amount (£1,666 a month) and the average return target (12%). Now I can calculate how long it should take my ISA to reach seven figures.

Note that I haven’t included platform fees, and the figures assume I reinvest dividends to really fuel compound returns. Naturally, it’s possible I might underperform, and individual dividends aren’t guaranteed.

YearAccrued interestBalance
1£1,099£21,091
5£34,031£133,991
10£170,210£370,130
15£486,407£786,287
17£691,168£1,031,032

In the above scenario, it’ll take me just under 17 years to reach £1m. Due to the power of compounding though, it’d only take another six years of regular investing to get to £2m!

Food for thought…

Investing in AI: 3 Stocks with Huge Potential!

🤖 Are you fascinated by the potential of AI? 🤖

Imagine investing in cutting-edge technology just once, then watching as it evolves and grows, transforming industries and potentially even yielding substantial returns.

If the idea of being part of the AI revolution excites you, along with the prospect of significant potential gains on your initial investment…

Then you won't want to miss this special report inside Motley Fool Share Advisor – 'AI Front Runners: 3 Surprising Stocks Riding The AI Wave’!

And today, we're giving you exclusive access to ONE of these top AI stock picks, absolutely free!

Get your free AI stock pick

Should you invest, the value of your investment may rise or fall and your capital is at risk. Before investing, your individual circumstances should be assessed. Consider taking independent financial advice.

Ben McPoland has no position in any of the shares mentioned. The Motley Fool UK has no position in any of the shares mentioned. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors.

More on Investing Articles

Businessman hand flipping wooden block cube from 2024 to 2025 on coins
Investing Articles

I bought 1,779 Legal & General shares 2 years ago – see how much dividend income I’ve got since

Harvey Jones holds Legal & General shares and has been pretty underwhelmed by their performance so far. The dividend is…

Read more »

Middle-aged black male working at home desk
Investing Articles

Is the FTSE 100 set to soar? Here are 3 ways to aim to cash in

My outlook for the FTSE 100 is definitely brightening as we get deeper into 2025. How can we make the…

Read more »

Investing Articles

£10k invested in NatWest shares on the ‘Liberation Day’ dip is today worth…

Harvey Jones looks at how NatWest shares have been knocked off course during recent market turbulence, but are now bouncing…

Read more »

Tariffs and Global Economic Supply Chains
US Stock

£5,000 invested in Nvidia stock just before the tariff news is now worth…

Jon Smith talks through the erratic movements in Nvidia stock over the past six weeks and reveals where an investor…

Read more »

Business manager working at a pub doing the accountancy and some paperwork using a laptop computer
Investing Articles

3 high-yield passive income stocks to consider buying right now

These stocks with big dividend yields look very tempting. Passive income investors could do well to consider taking the plunge.

Read more »

Handsome young non-binary androgynous guy, wearing make up, chatting on his smartphone, carrying shopping bags.
Investing Articles

Is a motley collection of businesses holding back this FTSE 100 stock?

Andrew Mackie explains why he's remained loyal to this FTSE 100 stock despite several of its businesses continuing to struggle…

Read more »

Businessman using pen drawing line for increasing arrow from 2024 to 2025
Investing Articles

3 top growth stocks driving wealth in my Stocks and Shares ISA

Our writer shines a light on a trio of outperforming growth firms in his Stocks and Shares ISA portfolio. They're…

Read more »

Young woman working at modern office. Technical price graph and indicator, red and green candlestick chart and stock trading computer screen background.
Investing Articles

Here’s where analysts expect the Lloyds share price to be a year from now

The Lloyds share price has fared well so far in 2025. But with some big issues on the horizon, can…

Read more »