Since 5 August 2013, AIM has been recognised as a stock exchange by HM Revenue and Customs which entitled its stocks to be eligible for Isas.
The move, which was first mentioned by Chancellor George Osborne in the March Budget, was cited as a potential boost for smaller businesses as a way to help growth and job creation.
Following the change, Alliance Trust Savings saw a 150 per cent increase in AIM trading compared to the previous two weeks. Over 50 per cent of all AIM share investments were carried out within an Isa or a Junior Isa account.
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The firm said that it had ensured all restrictions were removed from AIM stocks in time and trades were made as soon as the markets opened on 5 August.
Elaine Maddison, proposition and service director at Alliance Trust Savings, said: "Our customers have always shown a great thirst for investment choice. As soon as it was announced that AIM shares would be eligible, our customers were in contact asking when our platform would be able to facilitate this.
"We were delighted to execute the first AIM trade on the morning of 5 August and since then activity has increased throughout the week. We have over 700 AIM stocks on the platforms that clients can trade in online."

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