We all dream of becoming financially independent, and many of us try and achieve this by investing in a Stocks and Shares ISA. But did you know hitting a six-figure portfolio may be easier than you thought?

Based on past returns, I think it’s realistic to attain financial independence with jusy £5 a day. Let me illustrate how.

Thinking like Einstein

In almost all cases, the key to creating long-term wealth isn’t buying ‘Hail Mary’ assets like cryptocurrencies. Hugely volatile investments like these can produce uneven returns. They can also end up costing investors a lot more than they put in.

The most successful people tend to put their money in steady, reliable investments, and let time do the hard work for them. Albert Einstein is credited with describing compounding — which is where returns are rolled up over time to amplify total gains — as the eighth wonder of the world.

In this example, I’ll show you why.

A £318k-plus portfolio

What can you get for around £5 nowadays? A coffee, a Disney+ subscription, a peak-time trip on the London Underground.

Put into the stock market, and it could supercharge your chances of a comfortable retirement.

A fiver a day works out at £152.08 a month, on average. If used to buy equities, funds, and trusts in a Stocks and Shares ISA, that could build a beautiful £318,463 retirement pot after 30 years.

Sure, stock markets can be volatile at times. But over the long term they have proven an extremely effective way to generate capital. Since 2015, the typical Stocks and Shares ISA has delivered an average annual return of 9.64%.

At this level, it’s quite possible to eventually turn £5 into a portfolio worth more than £300,000.

A sensible approach

It’s important to remember that past performance isn’t a guarantee of future returns. However, spreading your investments across growth and dividend shares in multiple sectors and regions can improve your odds of hitting big targets

As well as buying individual shares, investors can effectively diversify with investment trusts and exchange-traded funds (ETFs). The HSBC S&P 500 (LSE:HSPX) is an ETF I’ve bought because of its stunning long-term returns.

Since November 2015, the fund’s delivered an average annual return of 14.4%. This is thanks in large part to the S&P 500‘s many high-performing technology stocks like Nvidia, Microsoft, and Amazon.

A blend of low US interest rates, the strong Stateside economy, and healthy foreign investment has also helped the fund deliver titanic returns. By tracking the entire S&P 500, it’s provided a diverse range of investing opportunities while still moderating individuals’ risk.

Though money is flowing out of Wall Street stocks and into other equities, I’m confident this HSBC ETF will remain an excellent wealth builder over time. It could turn even a modest £5 a day into a life-changing Stocks and Shares ISA.