The Alternative Investment Market (Aim) soared over the summer, taking its combined market cap to £80bn at the end of August.
The UK's junior market, which is designed to attract smaller companies to go public, climbed by 3.4 per cent in August. Combined with a sprinkling of new listings, the rise helped the index pass the £80bn mark for the first time since February 2014.
In total, there were 1,007 companies listed on Aim, giving an average market cap of £80m per firm, according to the figures compiled by Fundamental Asset Management (Fam).
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By contrast, the UK's two largest listed companies by market capitalisation, HSBC and British American Tobacco (BAT) are both worth more than the entire Aim. The bank, which recently mooted moving its headquarters back to Hong Kong, was worth £111bn at the end of August, according to official FTSE Russell data, while the tobacco manufacturers were valued at £88bn.
Despite the resurgence, the junior market is still significantly down on its all-time high market cap level of £108bn reached in July 2007.