Best AIM stocks of 2020

100 AIM companies rose at least 100% in 2020, and 28 surged more than 300%. Here are the year’s big winners.

Investors who bought £100 of Novacyt (LSE:NCYT) shares at the start of 2020 now have a remarkable £7,000 after the Covid-19 testing firm became the flagbearer for a stunning AIM year.

Novacyt has surged in value to more than £600 million after the deployment of its PCR kits for use in the rapid testing of NHS patients in the UK and by health authorities around the world.

• Invest with ii: Top UK Shares | Share Tips & Ideas | Open a Trading Account

Its 6,890% share price rise across 2020 transfixed retail investors — rising from 14p to way over 1,200p at one point in October before settling at 850p in December. But Novacyt was not alone in its success after exactly 100 AIM-traded companies more than doubled in value.

• Novacyt shares: an insider's view
• Mark Slater: why cheap UK market is a buy in 2021
• My favourite AIM share for 2021

Their performances were a fitting way for the junior market to celebrate its 25th anniversary as the AIM All-Share index easily outperformed the FTSE 100 index with the speed of its recovery from the pandemic sell-off, only bettered by the tech-fuelled Nasdaq. AIM's year-to-date rise of 15% is on a par with the S&P 500 and contrasts with a 15% fall for London's top flight index.

Fast-fashion chain ASOS (LSE:ASC) finished the year as AIM's biggest stock thanks to an improved market valuation of £4.5 billion, while video games business Keywords Studios (LSE:KWS) and clean energy firm ITM Power (LSE:ITM) topped £2 billion after big gains for their respective share prices in 2020.

Whereas speculative oil and gas explorers used to deliver many of the big share price gains in AIM, stocks with promising links to tackling the Covid-19 crisis have been the ones subject to a buying frenzy. Their enormous price rises partly reflect the uncertainty of the pandemic as no one knows how large the market will be or for how long the services will be needed.

But in the case of Novacyt, it has used the cash flows generated from its testing kits to pay down debt and to strengthen its long-term position across other areas of the diagnostics sector.

• Small-cap mining share tips for 2021
• What Bill Ackman thinks will happen to stocks in 2021
• Two star stocks and how to find them

Other 10-baggers since the March low point for AIM included Genedrive (LSE:GDR), which surged 3,000% up until May on the back of its point-of-care solution to detect the Covid-19 virus in saliva. Shares peaked at 220p but are now back at 50p, still double their level for the year.

Synairgen (LSE:SNG) was another hugely popular stock. Its shares rose 2,420% across 2020 after the respiratory drugs company disclosed positive results on a potential treatment for hospitalised Covid-19 patients. Phase III trial sites are now being set up in the UK and the former University of Southampton spin-off anticipates dosing the first patients soon.

The jump in shares since July means Synairgen is now worth £300 million, with the company the third most-bought AIM stock on the interactive investor platform — behind Novacyt and Boohoo (LSE:BOO) — during November's buying spree.

At one point in the year, Avacta (LSE:AVCT) was more popular with our clients than heavyweights BP and BT Group after the developer of Affimer-based biotherapeutics disclosed a partnership with Cytiva — formerly GE Healthcare Life Sciences — to deliver a rapid test for Covid-19. Shares have come off the boil in recent weeks but were still 538% higher over the year.

Away from the healthcare sector, Australia-focused explorer Greatland Gold (LSE:GGP) enjoyed another spectacular year on the back of its Paterson licences in the north west of the country.

Shares were 2p at the end of 2019 but hit a peak of 37p at the end of this year, giving Greatland a market value of more than £1.3 billion. The 1,840% rise in 2020 came as figures showed an initial resource of 4.2 million ounces on a gold equivalent basis for its Havieron project, making it more likely that partner Newcrest will elect to move forward with the development.

• Finding 10-bagger shares on AIM
• Best AIM companies of 2020 confirmed
• Why AIM has been the UK index to own in 2020
• Take control of your retirement planning with our award-winning, low-cost Self-Invested Personal Pension (SIPP)

The stronger gold price helping Greatland also benefited Canada's Orosur Mining (LSE:OMI), which rose by 583% amid progress on its Anza project in Colombia with Newmont and Agnico as partners.

Trading under the UFO symbol, Alien Metals (LSE:UFO) rose 424% after a big spike in its share price in the second half of the year, driven by the silver price and growing appreciation on the potential of its Elizabeth Hill project in Western Australia.