Why your 20s are the most powerful retirement decade
Money invested in your 20s has 40+ years to compound. At 7% average annual returns, £1 invested at 22 becomes £15 at 65. The same £1 invested at 35 becomes only £5.50.
This means the difference between starting at 22 vs 32, with identical monthly contributions, is often a £500,000+ gap at retirement. Nothing you do at 50 can recreate that lost decade of compounding.
The order of operations: what to do first
Step 1: Build a small emergency fund, at least 1 month of expenses, so an unexpected cost does not force you to stop investing.
Step 2: Contribute enough to your pension/401k to get the full employer match. This is an immediate 50–100% return that no investment can beat. Never leave free money on the table.
Step 3: Pay off high-interest debt (credit cards, personal loans above 7% APR). The guaranteed return of eliminating 20% APR debt beats any investment.
Step 4: Max out tax-advantaged accounts, ISA (UK), Roth IRA (US), or equivalent in your country.
Step 5: Invest any remaining surplus in a diversified low-cost index fund.
What to actually invest in
For most people in their 20s, the right answer is simple: a low-cost global index fund.
A global index fund like the MSCI World or S&P 500 gives you exposure to hundreds or thousands of companies in one fund. The cost is typically 0.1–0.2% per year, a fraction of what actively managed funds charge.
Index funds have outperformed the majority of professionally managed funds over every 10-year period in history. The evidence is overwhelming. Keep it simple, keep costs low, invest consistently, and do not panic when markets fall.
How much should you invest in your 20s?
The most commonly cited target is 15% of gross income toward retirement (including employer contributions). If that feels impossible right now, start with whatever you can, even 3%, and increase by 1% every time you get a pay rise.
The key principle: automate it. Set up an automatic transfer on payday before the money hits your spending account. You will not miss what you never see.
