Street Smart

Tree shakes: how market makers move small-cap prices

Tree shakes can make small-cap price moves look more alarming than they are. Here is how to read the screen without panic or misjudgement.

By James Beddington · May 24, 2026

A sudden price fall can feel like the market knows something you do not. The Street Smart Trader reminds us that, in thinner shares, the first thing to ask is simpler: who is moving the price, and what might they be trying to do? Understanding that pattern is one of the key lessons of the Street Smart approach.

In this article

The Short Version

A tree shake is a sharp price move designed to flush out nervous sellers or attract opportunistic buyers.
The book’s Pete example is historical, but the underlying lesson about liquidity and incentives still matters for modern investors.
Do not treat a sudden Level II move as automatic proof of hidden news.
Separate company information from market structure noise before you act.

What The Book Is Really Showing

The relevant Street Smart section follows a small-cap market maker through a volatile session. The detail is deliberately uncomfortable: the quoted price moves, the message boards light up, and traders watching the screen start inventing explanations before they have any evidence. The book calls this out as a structural feature of smaller shares.

The useful lesson is not that every price move is a tree shake or a trick. It is that a quoted price is not a pure message from the company. In a thinner share, the quote can also reflect the dealer’s inventory, the spread, order flow, and liquidity needs. Understanding the difference matters, which is also the core point in our guide to how market makers affect your trades.

The Historical Pete Scene

In the book, Pete is presented as a historical market-maker example from the pre-smartphone trading world. He manages a position in a small-cap share, moves the quote lower, watches who sells, then marks the price back up as buyers appear. This is the essence of a tree shake: test the holders, clear the weak ones, reset at a higher level.

That scene should be read as a dealer-side worked example, not as a current allegation about any named firm or platform. The numbers and screen behaviour belong to the book’s context. The concept that survives is the incentive problem: the person making a price may have motives that are not visible to the private investor watching the screen. The price and the news can be temporarily disconnected.

Why A Tree Shake Works

This dynamic works because it attacks confidence rather than fundamentals. A holder sees the price drop and wonders whether someone else knows something. A watcher sees the rebound and wonders whether they are missing a bargain. Both reactions can create the activity the market maker needs to manage the other side of a position.

This is why the book’s sceptical City perspective matters. It asks the reader to stop treating the screen as a neutral narrator. The screen shows prices, but it does not explain motives. A falling quote may reflect bad news, thin liquidity, a wide spread, a seller in size, or a dealer engineering a tree shake to find the other side of a trade. The task is to distinguish between these before acting.

What Has Changed Since 2010

The market structure around private investors has changed since the book was first published. The London Stock Exchange describes SETS as its flagship electronic order book, while the GOV.UK HMRC manual describes SETSqx as combining a limited electronic order book with a quote-driven facility. The point is not to memorise market plumbing. It is to understand that different shares trade through different structures, and the market’s behaviour differs depending on the venue and liquidity available.

The current regulatory language also matters. The FCA’s best-execution review frames execution quality around the result firms obtain for clients, including price, costs, speed and likelihood of execution. That does not make every poor fill suspicious. It does mean execution is a real obligation, and it pays to know the difference between a tree shake and genuine price discovery.

How To Read The Screen More Calmly

The practical response to a potential tree shake is to slow the decision down. Ask whether there is a company announcement, whether volume is unusual for this share, whether the spread has widened significantly, and whether the stock is thinly traded enough for quotes to move without much genuine information behind them. If the answer to the last question is yes, you are in tree shake territory.

This is also where the questions in two questions to ask before trading on any piece of market news become useful. Slowing down does not mean ignoring the move. It means separating the screen from the story before committing capital. If the only reason for action is that the screen has moved sharply, the book’s warning is doing its job.

A Simple Example

Imagine a small company whose shares are usually quiet. The bid drops sharply over a twenty-minute window, chat rooms start speculating about a profit warning, and a few nervous holders sell because they fear bad news. Then the quote reverses and short-term buyers rush in, buying shares from the sellers who just panicked. Nothing fundamental has changed about the company, but the price action has created its own convincing story.

The Street Smart lesson is to separate the story from the evidence. A tree shake produces price movement and noise. A genuine RNS, audited results or confirmed takeover approach is information. A sudden quote move without any announcement is a signal to investigate, not a reason to surrender your position or your judgement.

What This Means For You

If you invest in smaller UK shares, you are often dealing with less liquidity than the headline price suggests. That makes patience more valuable and hurried decisions more costly. Market orders, panic exits, and reflexive selling can hand control to someone with much better information about the order book. Recognising a tree shake is not about becoming cynical. It is about raising your evidence threshold before acting.

The sensible habit is to know why you own a share before the screen starts moving. If your investment reason is still intact after a sharp move, the move deserves investigation rather than an immediate exit. If your reason was only momentum or a message-board tip, the tree shake has already found the weak branch. That information is valuable too: it reveals whether your conviction was based on something real.

In Plain English

A tree shake is the market’s way of testing who is nervous. A market maker, or any large participant, pushes the price to see who folds. The price move may be real, but the story you attach to it may be invented. Slow down. Check whether there is an announcement. Look at volume. If nothing has changed at the company level, the tree shake has done its job and the price often recovers. The investors who hold through a tree shake with clear reasons tend to do better than those who sell on the story.

Reviewed by Cristoniq Editorial Team, 24 May 2026.