The six secret stocks that could supercharge your portfolio: With hundreds of options available, it can be difficult to pick out the best investments. These are our picks of smaller firms that should give you top returns

The London Stock Exchange is the world’s most international stock market, with businesses headquartered and operating in more than 100 countries. That is a huge bonus, allowing UK investors to benefit from opportunities overseas without leaving the comfort of the UK market.

Yet, with hundreds of options available, it can be hard to pick out the best investments, especially among smaller, lesser-known firms.

Midas has selected six that should deliver top returns, including three that have already proved their mettle: Airtel Africa, up nearly sixfold since I tipped the shares; Australia-based Empire Metals, which has soared more than 300 per cent; and Greenland-based Amaroq, which has more than doubled in four years.

Airtel Africa

In the UK, mobile phones and bank accounts are almost a given. More than 90 per cent of 16- to 64-year-olds own a smartphone, alongside the vast majority of senior citizens and far too many children. As for banking, fewer than 5 per cent of adults now rely solely on cash.

In Africa, the numbers are altogether different. Only a third of the population has a bank account and even fewer own a smartphone.

For Airtel Africa, this is a major opportunity. The company operates across 14 countries in Africa, from Nigeria to Madagascar, offering mobile phone and mobile money services, from the basic to the highly sophisticated.

Many customers start off with simple phones. But over time, the lure of the smartphone becomes too seductive. Airtel’s smartphone division is growing at about 20 per cent a year and should continue to expand at double digit rates.

Then there is Airtel Money, a unique service in Africa, allowing users to create a virtual wallet on even basic mobile phones so that they can transfer money and pay for goods without relying on cash.

Almost £150 billion of transactions were processed by Airtel Money last year alone and its prospects are bright as Africa has precious few bank branches, internet banking is in its infancy, and increasing numbers of people are looking for a safer and more efficient alternative to cash.

Airtel owns 79 per cent of Airtel Money and intends to float the business on the London Stock Exchange later this year. The group may keep its entire holding or reduce its stake and return the proceeds to shareholders.

More will be revealed in the coming months but either option should benefit investors.

Airtel Africa itself was floated in 2019 at 80p a share. The shares fell back during Covid, and Midas recommended them in 2020 at 57p. Today, they are £3.32.

Dividends are paid out too and there is every incentive to keep the dividend payments rising as the fabulously wealthy Bharti Mittal family own almost 80 per cent of the shares.

Investing in Africa is not for the faint-hearted but Airtel Africa proves how rewarding it can be. And the prospect of that Airtel Money flotation should provide a further boost.

Traded on: Main market Ticker: AAF Contact: airtel.africa

Amaroq

President Trump took office on January 20 last year. But even before then he had staked a claim to Greenland.

To many, this was one of Trump’s more surprising quests. To those in the know, it was obvious. Greenland is home to some of the world’s most valuable minerals – and Amaroq is one of its most active mining firms.

Founded just nine years ago, Amaroq owns licences across Greenland in varying degrees of readiness. One site is already in production: Nalunaq, a gold project expected to produce up to 35,000 troy ounces of gold this year, rising to more than 45,000 troy ounces in 2027.

Most gold mines produce less than 5 grams of gold per tonne of ore. This gem is delivering nearly 20 grams per tonne and should do even better in the coming years.

Dynamic chief executive Eldur Olafsson is also hoping to bring nearby Nanoq into play soon, a huge deposit which could boost Amaroq’s gold production by at least 20 per cent.

Nalunaq and Nanoq are both in southern Greenland, but Amaroq owns yet another major asset in the western part of the country: Black Angel.

In production from 1973 to 1990, the mine has lain dormant since then, but Olafsson is bringing it back to life. The site is already known for zinc, lead and silver, but Amaroq has also discovered two strategic minerals in the area: germanium and gallium.

Germanium is a vital mineral for defence, telecoms, aerospace, and satellites, while gallium is a core component of computer chips and solar panels.

Amaroq moved from the London Stock Exchange’s junior AIM market to the main market last month and recently delivered stellar interim results, with brokers predicting profits of £31 million this year, more than doubling in 2027.

Amaroq shares have soared from 44p to £1.04 since Midas tipped them in 2022. More gains are expected.

Traded on: Main market Ticker: AMRQ Contact: amaroqminerals.com

Prospex Energy

Energy security was seldom discussed outside rarefied circles until Russia invaded Ukraine in early 2022. Since then, home-grown power has become an issue of critical importance, even more so since America’s ill-fated war with Iran.

Prospex Energy is well placed to benefit from this new reality. Traded on AIM, the group owns oil and gas projects in Italy, Spain, and Poland – some in production, others at an earlier stage, but all with significant growth potential.

The business was formed as an investment company, designed to buy assets, improve them, return money to shareholders, and continue the cycle.

Previous management focused more on purchases than sales and investors showed their disappointment, sending the shares plunging from 74p to 3.7p over a decade.

Now, change is under way under new chief executive Tom Reynolds, a no-nonsense Scot with a history of delivering for investors.

He has systematically analysed the business, with the aim of funding development and bolstering the share price without asking shareholders for cash.

Italy is home to Prospex’s most profitable asset, a gas project in the Po Valley. One well is operational, but there are plans to add four more, generating significant gains over time. Prospex owns almost 40 per cent of the site, but it may bring in outside partners to contribute to any future cash calls.

Spain boasts two sites, one near Seville in the south and one in the heart of Rioja in the north. The first is wholly owned by Prospex, in production and hoping to expand once permits are granted.

The Rioja asset is also likely to deliver big improvements next year, but Prospex owns just 7.5 per cent of it and may reduce that still further.

Poland is a new addition to the group, with two licences acquired this year, including an area where oil was discovered in Soviet times and which could move into production in the next couple of years.

Prospex today is valued on the stock market at little more than £16 million. Yet its assets could be worth more than £200 million if Reynolds’ plans come to fruition.

That is a big ‘if’ but there is little doubt that energy assets are in demand and Prospex has some good ones. At 3.7p, the shares are a buy for the adventurous investor.

Traded on: AIM Ticker: PXEN Contact: prospex.energy

Empire Metals

Titanium dioxide is one of the most widely used compounds in the world – a central ingredient in paints, packaging and paper, as well as make-up and sunscreen.

Pure titanium is more rarefied, but it plays a key role in aerospace and defence. So much so that the metal has been designated a critical mineral by the US, the UK, and the European Union. Even our bodies respond well to titanium, so it can be found in hip and knee replacements, dental implants and screws that bind joints together.

The global market in titanium is valued at around £15 billion a year and expected to grow by some 20 per cent over the next five years. But premium titanium and titanium dioxide are in short supply, with China controlling much of the market. Empire Metals could change that dynamic.

Operating in Western Australia, this AIM-traded company has just announced the world’s largest resource – eight billion tons of ore containing almost 350 million tons of high-grade titanium dioxide.

Most of the world’s titanium and related compounds come from low-grade ore that needs extensive, expensive and polluting processing. Empire’s raw material is of a superior class, which means processing costs will be lower, production will be cleaner, and the end product will be tip top.

Empire is sitting on a vast 400-square-mile site, and work is at an early stage. But the shares have already soared from 9.5p to 42p since January 2024 and they should continue to move higher.

Recent interim results confirmed that the group is making progress on every front and plenty more news is expected over the coming months. The group also plans to list in Australia, while retaining its London home, a move that should bring in new investors.

Existing shareholders may want to take some profits, but brokers suggest the stock is worth close to 80p, implying long-term value for new and current holders.

Traded on: AIM Ticker: EEE Contact: empiremetals.com

Nippon Active Value Fund

About 4,000 companies are listed on the Japanese stock market, almost twice as many as on the New York Stock Exchange.

Many are so poorly managed and ill-suited to life alone that Japanese regulators believe half will be taken over or disappear entirely. But the pace of change is slow, so firms stagnate, run by octogenarians more focused on their own financial comfort than generating value for shareholders.

Nippon Active Value Fund (NAVF) was formed to spot these under-achievers, shake them up and generate returns for investors. The group invests in small and medium-sized companies listed on the Nikkei Exchange, and there are 29 companies in the portfolio, from chocolate-maker Ezaki Glico to cleaning materials firm Stellar Chemifa, whose customers range from nuclear plants to chip-makers.

Fuji Media is a classic example of NAVF at work, selected when the TV group was led by Hisashi Hieda, then in his late 1980s. A scandal triggered boardroom resignations, the shares rose and NAVF more than doubled its money.

NAVF also benefits from American firepower in the shape of fellow investment funds, Dalton and NAVF Select. The trio hunt in a pack, so they can build larger stakes and exert more influence.

The track record is promising. At launch in 2020, NAVF was valued at £103 million. Today it is worth almost £450 million. Smaller companies have lagged their larger peers in Japan this year, but chairman Paul Ffolkes Davis and his team are undaunted and could deliver some exciting action over the coming months. That should benefit fund investors, making NAVF an intriguing buy at £2.28.

Traded on: Main market Ticker: NAVF Contact: nipponactivevaluefund.com

MP Evans

Palm oil arouses strong emotions. Producers are accused of killing off orangutans, turning forests into scrubland, and putting profit over local livelihoods.

However, Indonesia-based MP Evans takes a different tack, focusing on sustainable production, with certificates and independent audits to prove it.

Trees are planted in carefully selected areas, wildlife corridors wind through each plantation and the group also works closely with local communities.

Midas first tipped MP Evans in 2011 when the shares were £4.20. Today they are £17.70. The increase reflects a huge increase in acreage and efficiency, as well as rising palm oil prices.

Exceptionally versatile, palm oil is used in 50 per cent of all packaged foods, from biscuits and bread to Nutella and ice-cream.

Cosmetics contain palm oil too and increasingly the oil is used as biofuel, including in Indonesia. This is driving up demand, with prices up more than 25 per cent this year alone.

Chief executive Matthew Coulson is optimistic. Profits of $134 million (£98 million) are expected this year and he is hoping to take that number higher.

Dividends are rising too, with 62.5p pencilled in for this year, climbing to 65p next year.

MP Evans is valued on the stock market at nearly £1 billion, but a family ethos pervades the business. Edwin Hadsley-Chaplin joined in 1947, stayed for decades and his son Peter now chairs the company, while his family still owns about 10 per cent of the shares. That translates into careful stewardship and a determination to deliver sustainable growth across generations.

For investors with long-term horizons, MP Evans is a buy.

Traded on: AIM Ticker: MPE Contact: mpevans.co.uk