By finding the best penny stocks to buy, my portfolio could earn phenomenal returns over the coming years. After all, when these tiny businesses succeed, it’s not unusual to see triple or even quadruple-digit gains over the long run.

Sadly, finding these winners early on is far easier said than done. After all, there are hundreds of very small penny shares to pick from. But luckily, institutional investors have already started narrowing down the list with their own research. And as of April 2026, there are three tiny stocks that have the potential to be big winners.

Let’s dive in.

3 top professional picks

The three small businesses that institutional analysts have flagged as potentially terrific buys in 2026 are Synthomer (LSE:SYNT), Topps Tiles (LSE:TPT), and Michelmersh Brick Holdings (LSE:MBH).

Each company is fairly unique, but they all target one end-market: construction.

Synthomer, in addition to other products, supplies specialist polymers used in external paints, architectural coatings, and waterproof membranes for roofs. Topps Tiles is the UK’s leading specialist wall and floor tile retailer, supplying both home renovators and home builders. While Michelmersh is trying to help solve the UK’s chronic shortage of clay bricks.

Each business supplies a different part of the construction sector’s value chain. As such, this basket of stocks appears well-positioned to capitalise on the structural tailwinds created by the government’s commitment to build 1.5m new homes without directly competing with each other.

If the share price forecasts are right, investors could be in for some impressive gains over the next 12 months, and possibly even bigger returns over the coming years.

Needless to say, a combined 51.4% potential gain by this time next year certainly suggests that these businesses might indeed be among the best stocks to buy now.

But what’s the catch?

The risks

Despite the government setting ambitious supportive homebuilding targets, the UK construction sector remains genuinely weak on the back of rising raw material and labour costs, made worse by a continuous unaffordable-housing crisis.

As a result, all three businesses are struggling to achieve meaningful revenue and profit growth, with the pressure only amplified for Synthomer and Topps Tiles, whose balance sheets carry heavy debt burdens.

This impact has only been made worse by the escalating geopolitical environment, with costs being driven even higher.

What does this all mean for investors?

The bottom line

While each company has a genuine path to success, external headwinds could nonetheless prevent them from achieving their full potential. And without deep coffers to help absorb the short-term impact, these penny stocks could see their share prices fall much further before a cyclical recovery emerges.

Personally, out of this basket, Michelmersh appears to be in the strongest position, leveraging superior aesthetics and durability to generate some pricing power in a highly commoditised brick market. In fact, that’s why the company now enjoys the biggest operating margins out of the three.

So, while I’m not 100% convinced that Michelmersh is among the best stocks to buy now, it certainly has enough potential to warrant closer inspection.