Building Wealth by Buying the Whole Haystack
- Dec 18, 2025
- 5 min read
Updated: Jan 7
Investing often seems complex and risky, but it doesn’t have to be. This guide will help you cut through the jargon. You’ll learn about risk and how to build long-term wealth on your own.
What is Index Fund Investing? (Buying the Whole Haystack)
Index fund investing is a straightforward approach. Instead of picking individual companies, you buy the whole market at once—essentially buying the "whole haystack."
Passive Management: An index fund is a passive investment. There’s no manager actively selecting assets.
Diversification: It invests in every equity or bond within a specific index.
Lower Costs: These funds provide diversification at a lower cost than actively managed funds.
Broad Exposure: When you buy shares in the fund, you gain exposure to all the companies on that list. It’s an "off-the-shelf" investment where one transaction spreads across hundreds or thousands of companies.
For example, the FTSE 100 includes the 100 largest companies in the UK stock market, while the S&P 500 comprises the 500 largest companies in the US. A global index can include equities or bonds from markets worldwide.
The goal of an index fund is not to pick individual companies that will outperform the market. Instead, you aim to capture the growth of the market as a whole.
How Index Funds Work: Weighting and Allocation
Most companies in an index fund are weighted by size. This means you get more exposure to larger companies and less to smaller ones.
These weights change as companies grow or decline. For instance, if a company like Microsoft fades, the fund's allocation to it automatically shrinks.
Currently, the American stock market makes up about 60% of the global stock market. When you buy a global index fund, around 60p of every pound goes into US investments. Within this, Microsoft is so significant that 5p in every £1 goes just to them.
Investing in the whole haystack means you don’t need to analyse each individual company.
Understanding Risk and Volatility
Building a portfolio relies on understanding your appetite for risk and how that shapes your asset allocation.
Assessing Your Time Horizon
Firstly, consider how long you have until you need the money. For example, if you’re saving to buy a house, it doesn’t make sense to take too many risks with that money.
On the other hand, if you don’t need the funds for a long time (10 years or more), you may be comfortable with more risk. This understanding can lead to potentially higher returns.
Emotional Resilience
Secondly, consider how much you can tolerate seeing the value of your investments drop.
How would you react if your portfolio dropped 20% in one morning? Or if it declined every year for three years? These scenarios have happened in the last 40 years. If you can’t cope with such declines, a 100% stock market portfolio may not be for you.
Investments with the highest growth potential also carry the highest chance of volatility or price declines.
If you find that you couldn’t physically, emotionally, or financially cope with a decline in your portfolio’s value, then investing 100% in the stock market isn’t suitable for you.
The Solution: Combining Stocks and Bonds
Combining stocks and bonds is a traditional way to reduce portfolio volatility.
Risk and volatility are often used interchangeably in the financial press. Volatility measures how far the price of an asset moves up or down, while risk refers to the likelihood of an asset losing value.
Equities typically provide higher returns than bonds, but they are more volatile. This means regular big ups and downs in value, leading to a higher risk of loss. Conversely, bonds offer lower returns with reduced volatility, resulting in less risk of loss. This is why we buy both equities and bonds.
Comparison of Returns (2014–2024)
Historical data shows why long-term investing in indices is a powerful wealth-builder:

If you’re saving for retirement through a SIPP or company pension scheme, which likely spans 40 to 50 years, you can afford to have higher exposure to equities.
Strategy: K.I.S.S. (Keep It Simple, Stupid)
The possibilities for structuring investments are endless, but the key is not to overcomplicate things.
You don’t need to add 100 different funds to your portfolio if they all serve the same purpose. If your goal is to be 100% in equities with global exposure, one global all-cap index might suffice.
You don’t have to make every decision today. You will gain confidence and knowledge as you develop over time, and so will your portfolio.
When is the "Right Time" to Invest?
Everyone searches for the perfect time to start investing. Many wait for a "dip" or a "crash," but this often leads to never starting at all.
If you’ve decided to invest every month for the next decade or three decades, does it make sense to sit on the sidelines stressing about the first £100?
A long-term ongoing investment into the market consistently is often referred to as pound cost averaging. This means investing a set amount regularly, for example, £50, £100, or £500 a month, regardless of market conditions. The opposite is lump sum investing, where you invest all your money at once.
Pound cost averaging is arguably the simplest and most effective strategy to combat timing temptations and benefit from volatility:
When prices are high, your £100 buys fewer shares.
When prices drop, your £100 buys more shares.
Over time, this averages out your purchase price and drastically reduces the risk of investing a large sum right before a crash. It removes emotion from the equation and turns market dips into an automatic advantage. It’s the perfect strategy for steadily building wealth through all market conditions.
When Should I Sell?
“I’m up 20%, I’m going to sell, then I’ll rebuy when the prices come back down.”
Predicting when stocks will rise or fall is very challenging and can be stressful. Selling because you’re "up 20%" can backfire if the market continues to climb. This is why we say “Time in the Market, not Timing the Market.”
The general guidance many advisers give is to be consistent, ignore the press, and disregard short-term price movements. Stick to your plan; the only thing that truly matters is where your portfolio stands when you plan to sell.
Conclusion: The Path to Wealth
Buying and holding a portfolio of low-cost, passive, global index funds (equities and bonds) reduces risk by spreading your money across thousands of global businesses. Through diversification, lower costs, and the magic of compound interest, this strategy is designed to make you wealthy.








Good explanation gradragtoriches.