Why low price doesn’t mean cheap
The price of a single share is meaningless without knowing how many shares exist. A company with 1 billion shares at 1p each has a market cap of £10 million. A company with 10 million shares at £1,000 each has a market cap of £10 billion. The cheaper-looking share is from the far less valuable company. This confusion — the idea that a "low" share price must mean the stock has room to grow — is one of the most exploited misconceptions in investing. Companies often issue large numbers of shares at very low prices specifically to create this illusion.
The pump-and-dump risk
Because penny stocks trade in thin markets with few buyers and sellers, small amounts of buying can move prices dramatically. Fraudsters exploit this: they accumulate shares in a penny stock, then promote it aggressively through social media, stock tips newsletters, and email campaigns — creating artificial demand that drives the price up. Once the price has risen, they sell ("dump") their shares into the buying frenzy, the buying dries up, and the price collapses — leaving latecomers with large losses. This scheme is explicitly illegal under UK and US securities law but is extremely common in the penny stock market.
Liquidity and spread problems
Penny stocks often have wide bid-offer spreads — you might see a "price" of 5p but the best offer at which you can actually buy is 7p, and the best bid at which you can sell is 3p. This 4p spread represents an 80% round-trip cost on a 5p stock. When you want to exit, you may find no buyers at any reasonable price — the volume simply isn’t there. The lower the market cap and the less regulated the exchange, the more extreme these liquidity problems become.
“The penny stock market is where retail investors go to learn expensive lessons. The tuition is usually total loss of capital.”
What this means for you
Treat any unsolicited tip about a penny stock — from email, social media, WhatsApp groups, or Discord servers — as presumptively a fraud. The pattern is almost always the same: an exciting story about a revolutionary product or imminent news that will make the stock "explode." If you are interested in small-cap investing for the genuine return premium it can offer, stick to listed small-cap companies on regulated exchanges (AIM in the UK, Russell 2000 constituents in the US) with audited accounts and analyst coverage — not unregulated OTC penny stocks where the deck is stacked heavily against the retail investor.