When the Free Shares Arrive: A UK Small-Cap Guide to Lock-Up Expiries

A UK listing is often described as a single event: the offer price is set, the shares begin trading and the market delivers its verdict. For small-caps, that verdict is rarely final. The more useful date may sit months later, when the first lock-up expires and a block of previously restricted shares becomes eligible for sale. In thin order books, that calendar can shape prices as much as the admission document did.

What a lock-up actually locks

A lock-up is a contractual restriction on selling shares for a set period after an IPO, placing or other issue. It usually binds the company, directors and certain existing shareholders, and it is arranged with the bookrunner or underwriters to support an orderly aftermarket. Typical periods range from six to twelve months for institutional holders, with founders and some long-term investors agreeing to longer terms. Placings by listed companies often carry shorter restrictions.

The key point for investors is that lock-ups are rarely one date. Admission documents and placing agreements frequently contain staggered releases: one tranche at three months, another at six, a larger block at twelve. Some shares may be released early by waiver. Others may remain restricted by separate arrangements. The offer price tells you what buyers paid at admission. The lock-up schedule tells you when supply may change.

Why the calendar can outrank the offer price

UK small-cap order books are shallow. A company may trade only a few hundred thousand shares a day, and spreads widen quickly when volume arrives. If a lock-up expiry frees shares equivalent to twenty or thirty days of normal trading, the market does not need a seller to act immediately for the price to react. The prospect of supply is often enough. Investors begin to anticipate the date, liquidity providers widen quotes, and the stock can drift before any restricted holder has sold a single share.

This is why two companies with similar offer prices can behave very differently after admission. One may have a single founder holding most of the register, with a long lock-up and no obvious need to sell. Another may have several venture or private-equity holders whose funds are nearing the end of their lives. The second company faces a more visible supply overhang, even if its business is performing well.

The signal in early releases and waivers

Waiver announcements deserve close reading. A bookrunner may agree to release shares early, sometimes to improve liquidity, sometimes because a holder has a genuine need to sell. The announcement itself is a fact; the reason is often less clear. Investors should ask whether the waiver covers a small employee tranche or a large institutional block, whether it was requested by the company or the holder, and whether it coincides with other corporate news.

Director intentions are another useful but limited guide. A statement that a director has no current intention to sell is not a binding commitment. It can still be informative when read alongside the director’s holding size, recent dealing history and any personal financing arrangements disclosed in the admission document. A founder who has already taken cash at IPO may have different incentives from one who retained a large stake.

Reading the order book before the date

The practical test is to compare the locked-up shares with the market’s capacity to absorb them. Take the number of shares due for release and divide it by average daily volume over the preceding month. That gives a rough measure of days of trading needed to clear the block, assuming all holders sell. Most will not, but the ratio still shows how much the order book could be tested.

It also helps to separate holder types. Private-equity and venture holders often face fund-life pressures and may be more likely to exit. Employee shareholders may receive small lots and sell gradually. Founder holdings may be released but retained for control or income reasons. The same number of shares can mean different things depending on who owns them.

A calendar-based checklist for 2026

1. Find the exact expiry date in the admission document, placing agreement summary or relevant RNS. Do not rely on a secondary source.
2. Map every tranche. Note whether releases are staggered and whether any shares are subject to separate restrictions.
3. Calculate the released shares as a percentage of free float and as days of average daily volume.
4. Review the history of waivers and early releases. Repeated waivers can indicate pressure or a more flexible register.
5. Read director intention statements and any recent dealings. Treat them as context, not guarantees.
6. Monitor RNS announcements in the thirty days before expiry. Look for changes to lock-up terms, board changes and trading updates.
7. Check whether the company sits near an index or liquidity threshold that could amplify a rebalancing effect.
8. Set review points at thirty days before, ten days before, the expiry date and thirty days after. Compare price and volume behaviour with the pre-expiry period.

What not to assume

A lock-up expiry is not a sell signal in itself. Many holders retain shares beyond the restriction, and some releases are technical rather than commercial. Nor is a quiet expiry a guarantee of support. Thin books can exaggerate both directions, and a single large seller can move a small-cap price without telling you anything about the company’s prospects.

The better approach is to treat the lock-up calendar as a supply map. It tells you when the register could change, who might be free to act and how much the order book may need to absorb. For UK small-cap investors in 2026, that map is often more useful than the admission-day headline.