AIM Market Guide 2026: Opportunities, Risks & How DipBuster Screens It

AIM — the Alternative Investment Market — launched in 1995 and has grown into the world's most successful growth market by number of companies listed. For a Graham-style investor, it's simultaneously the most fertile hunting ground for net-nets and the most treacherous market in the UK. Here's a complete guide for 2026.

What Makes AIM Different

AIM companies are not required to meet the same admission criteria as Main Market issuers — no minimum market cap, no minimum trading history, no profitability requirement. This creates two things: a vast opportunity set of underfollowed, underresearched companies, and a far higher proportion of poor businesses that will never create shareholder value. Rigorous screening is essential.

DipBuster's AIM Screening Approach

We apply four additional filters to AIM stocks beyond our standard NCAV screen: (1) minimum £10m market cap to exclude genuinely illiquid shells, (2) positive operating cash flow in at least 2 of 3 years, (3) no qualified audit opinion in the last annual report, and (4) confirmed ISA eligibility. These filters cut the AIM universe by approximately 60%, but dramatically reduce the proportion of value traps in the remaining set.

The IHT Angle

AIM shares held for more than two years in an ISA qualify for Business Property Relief, making them IHT-exempt. For investors with larger portfolios in IHT planning mode, an AIM basket serves double duty: value investing returns plus estate planning. This is a genuinely distinctive advantage vs other markets.