If Someone Handed Me £500,000 to Invest Today, Would I Put It All in Nvidia?

Introduction

If someone gave me £500,000 to invest today, where would I even start?

It is tempting to put everything into Nvidia. AI is everywhere in the news, and Nvidia’s share price has been climbing rapidly. Another option would be energy, since oil recently pushed above $90 a barrel (Reuters, 2025). Both are exciting opportunities, but are they enough to build a resilient portfolio?

From what I have been learning, relying on one investment is like taking only one scan in radiography. You miss the full picture. In investing, the same principle applies; balance is what keeps you protected when markets shift.

The Allure of Nvidia

Nvidia has become the face of artificial intelligence. Its GPUs power the technology behind almost every major AI breakthrough, and this dominance has pushed its stock to impressive heights (Financial Times, 2025). With the US Federal Reserve recently cutting rates by 0.25 percent (CNBC, 2025), growth companies like Nvidia and Microsoft may have even more room to expand.

It is an exciting story, but no company is invincible. Tech is volatile, and risks such as regulation or competition can quickly change the outlook.

The Case for Energy Stocks

Oil prices recently passed $90 a barrel (Reuters, 2025). Energy stocks often act as a hedge during inflationary periods or economic slowdowns, and many companies in the sector provide dividends that add stability compared to high growth technology.

However, oil markets are unpredictable. They are heavily influenced by politics and global events, and prices can swing dramatically. Betting too much on oil can expose an investor to shocks that are out of their control.

Risks of Concentrated Investments

When I compared these two options, I thought about something from my radiography background. One scan is rarely enough to diagnose a patient. We take different views to avoid missing any fractures or pathologies.

Investing works in the same way. Putting everything into one stock like Nvidia, or one sector such as energy, leaves you exposed. Diversification reduces that risk and balances out returns over time.

The Importance of Portfolio Diversification

So how would I actually invest £500,000?

I would put half into equities, splitting between growth companies such as Nvidia and Microsoft and defensive companies such as Unilever and AstraZeneca. A quarter would go into bonds, using iShares UK Gilts and US Treasuries, which are attractive while the Bank of England holds rates at 4.0 percent (BBC, 2025). Twenty percent would be in ETFs, using the S&P 500 and FTSE All-World for global exposure. The remaining five percent would be kept in cash, which is especially useful with signs of weakness in the UK housing market (The Guardian, 2025).

This balance means growth is captured while defensives and bonds provide stability. ETFs reduce concentration risk by spreading exposure globally, and cash provides flexibility to act quickly when opportunities or shocks arise.

Portfolio Allocation (£500,000)

For this case study, I imagined a 35-year-old tech consultant who hopes to retire in 20 years with steady wealth growth. Their risk appetite is medium, meaning they want the chance to grow their money but not in a way that causes constant stress when markets swing. With that in mind, I built the portfolio to be balanced and adaptable.

Half of the portfolio, around £250,000, would go into equities. To capture growth, I chose companies such as Nvidia and Microsoft that are driving innovation in technology and AI. To balance that, I added more defensive companies like Unilever and AstraZeneca, which tend to perform more steadily even when markets are uncertain.

Another £125,000 would go into bonds, mainly UK gilts and US Treasuries. Bonds are less exciting than stocks, but they provide stable income and reduce overall risk, which suits someone planning for the long-term.

I would also invest £100,000 into ETFs, including the S&P 500 and FTSE All-World. These funds give broad global exposure, making sure the portfolio is not too dependent on a single market or sector.

The final £25,000 would be held in cash. This might not earn much, but it provides flexibility. If opportunities come up or if markets face sudden shocks, there would be liquidity ready to respond.

This allocation gives a mix of growth, stability, and flexibility, which I felt was the most realistic approach for a medium-risk investor with a 20-year horizon.

Asset Breakdown (£500,000)

The biggest part of the portfolio goes into equities, about £250,000. Like I mentioned earlier, I chose a mix of growth and defensive companies because I wanted both growth and stability. Nvidia and Microsoft are clear growth picks, especially with the US Federal Reserve recently cutting rates by 0.25 percent (CNBC, 2025). Lower borrowing costs usually make it easier for tech companies to expand, which supports their case. On the other side, I included Unilever and AstraZeneca as defensives. With UK inflation stuck at 3.8 percent (BBC, 2025), households may cut back on luxuries but essentials like food and healthcare remain steady, which keeps these companies more resilient.

For bonds, I set aside £125,000. I know they do not grow as fast as stocks, but they help smooth out the ride. With the Bank of England keeping rates at 4.0 percent (BBC, 2025), gilts and US Treasuries look reliable for steady income and protection if equities fall.

I also wanted broader exposure, so £100,000 went into ETFs. The S&P 500 and FTSE All-World give access to markets beyond the UK. This feels especially important now, since oil prices have gone above $90 a barrel (Reuters, 2025). Events like that can shake entire markets, and ETFs help reduce the risk of being too tied to just one sector or country.

The last £25,000 stays in cash. It is not exciting, but it is useful. If something unexpected happens, like the slowdown we are already seeing in the UK housing market (The Guardian, 2025), having cash ready means I can respond without having to sell other investments at the wrong time.

When I put all of this together, I felt like each part of the portfolio had a clear role. Equities give growth, bonds add stability, ETFs spread the risk, and cash provides flexibility. It feels balanced, and it also feels realistic when thinking about what is happening in markets right now.

Personal Insights and Reflections

As a student, this was not just about theory. It showed me how easy it is to get swept up by headlines like AI or oil and forget about balance.

I do not actually have £500,000, but I have been practicing through SimTrade simulations and IG’s demo account. Both have been helping me see how quickly markets can change and how important it is to adjust decisions rather than just set and forget them. These experiences have taught me that diversification protects you, just like multiple scans reduce blind spots in radiography, keeping some cash on the side is more powerful than it looks, because it gives you flexibility to react. Another big lesson has been how much markets react to news. Whether it is a rate cut from the Federal Reserve or oil prices moving higher, headlines often drive decisions just as much as numbers on a spreadsheet.

Stress-Testing the Portfolio

It is one thing to design a portfolio for the present, but I also wanted to see if it could stand the test of time. To do this, I stress-tested the allocation against past events such as the 2008 financial crisis, the 2011 Eurozone debt crisis, and the 2020 COVID crash. Each of these moments challenged markets in different ways, and they helped me think about how diversification actually works when things go wrong.

Looking back at these scenarios reinforces the same lesson I have been learning as a student: diversification does not prevent losses completely, but it reduces the extremes and gives more flexibility to adapt when markets are under pressure.

Conclusion

If I actually had £500,000 to invest, it would be tempting to put it all into something exciting like Nvidia or to lean heavily on oil while prices are high. But working through this case study has shown me that chasing headlines is not the same as building a portfolio that lasts. What matters more is balance.

By spreading money across equities, bonds, ETFs, and even a small amount of cash, I created something that can grow over the next 20 years without being dependent on one single story. The stress-test against 2008, 2011, and 2020 made that even clearer. Diversification does not prevent losses altogether, but it reduces the extremes and gives room to respond when markets are under pressure.

For me, this exercise was more than just numbers on a spreadsheet. It was a way to connect what I am learning in finance with skills I already know from radiography, like looking at multiple views to get the full picture. I am still a student, and I am still learning, but this process helped me think more like an asset manager. My next step is to keep practicing, testing my decisions, and building confidence so that when I do have to make real choices for clients one day, I will be ready.

Supporting Material

This blog expands on a case study I created called “How I Would Invest £500,000”. That project was based on the profile of a 35 year old tech consultant aiming to retire in 20 years with steady growth and a medium tolerance for risk. The case study focused on portfolio allocation and used visuals to explain the breakdown, while this blog looks deeper into the market context, news influences, and my personal reflections. Click on the link to view the original case study https://www.dropbox.com/scl/fi/9tx399o5h399ixebzvkl6/how_i_would_invest_ps500k-2.pdf?rlkey=2a97lgy2z9o8wdc08f3zm3try&st=ipuemtjq&dl=0