Evidence over opinion Issue 2026
Rational GB Evidence-based money

Guide collection

Investing Foundations

Investing Foundations reviews, comparisons and buying guides from Rational GB.

7 guides / Updated 2026 / Independent & evidence-checked
How to Start Investing in the UK: An Evidence-Based Beginner’s Guide No. 01
Investing Foundations No. 01

How to Start Investing in the UK: An Evidence-Based Beginner’s Guide

Start investing in the UK in 2025/26: ISA allowances, named low-cost index funds, real platform fees, FSCS limits and the long-run evidence on returns.

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Active vs Passive Investing: What the Evidence Actually Says No. 02
Investing Foundations No. 02

Active vs Passive Investing: What the Evidence Actually Says

UK evidence on active vs passive investing: SPIVA data, fund fees, persistence and the narrow case for some active. A calm, research-led verdict.

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How to Buy Your First Index Fund: A Step-by-Step Walkthrough No. 03
Investing Foundations No. 03

How to Buy Your First Index Fund: A Step-by-Step Walkthrough

A sober, step-by-step UK guide to buying your first index fund: ISA vs SIPP, choosing a platform, Acc vs Inc units, fund vs ETF, and placing the order.

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Lump Sum vs Pound-Cost Averaging: Which Wins, and When No. 04
Investing Foundations No. 04

Lump Sum vs Pound-Cost Averaging: Which Wins, and When

UK evidence: lump sum beat drip-feeding 68% of the time. What pound-cost averaging really buys you, and how to phase in inside your ISA.

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Asset Allocation Explained: How Much Should You Hold in Stocks vs Bonds No. 05
Investing Foundations No. 05

Asset Allocation Explained: How Much Should You Hold in Stocks vs Bonds

A UK guide to setting your stocks vs bonds allocation by risk capacity, not age, with gilt tax rules, the 2022 60/40 stress test and rebalancing.

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How Much Should You Invest Each Month? A Simple UK Framework No. 06
Investing Foundations No. 06

How Much Should You Invest Each Month? A Simple UK Framework

There is no single right number. Use this UK order-of-operations to decide if you should be investing yet, then set a monthly amount you can keep up.

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Risk Tolerance and Time Horizon: Choosing a Portfolio You Can Stick With No. 07
Investing Foundations No. 07

Risk Tolerance and Time Horizon: Choosing a Portfolio You Can Stick With

A UK guide to picking an investment risk level you can actually hold through a crash: attitude to risk, capacity for loss and time horizon explained.

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