Street Smart

Pete and the tree shake: a market maker’s day in plain English

Tree shakes can make small-cap price moves look more meaningful than they are. Learn how to read the screen without panic, advice or guesswork.

By James Beddington · May 22, 2026

A sudden price fall in a small-cap share can feel like the market knows something you do not. The Street Smart Trader asks us to pause before jumping to conclusions: in thinner shares, the first question is simpler: who is creating this move, and what might they want from it?

Reviewed by Priya Nair, Editorial Director · May 22, 2026, 21:45

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.
Do not treat a sudden Level II move as automatic proof of hidden news.
Modern investors should separate company information from market structure noise.

What The Book Is Really Showing

The relevant Street Smart section introduces readers to a tree shake market maker scenario through one deliberately uncomfortable example: a small-cap dealer moves the quote lower, message boards light up, and traders watching the screen start inventing explanations before they have any evidence.

The useful lesson is not that every price move is a trick. It is that a quoted price is not a pure message from the company. In a thinner share, the quote also reflects inventory, spread, order flow, liquidity and the dealer’s need to create a two-sided market.

The book’s value here is that it gives retail investors a rare dealer-side perspective. Most coverage of small-cap markets focuses on the company side: results, directors’ dealings, broker upgrades. The Street Smart Trader switches the camera angle and shows how a market maker managing a position experiences the same stock. Understanding how the tree shake market maker dynamic operates reframes the key question from “what is the company telling me?” to “who else is in this market, and what are they trying to achieve?”

The Historical Pete Scene

In the book, Pete is presented as a historical tree shake market maker example from the pre-smartphone trading world. He is managing a position in a small-cap share, moving the quote lower, watching who sells, then marking the price back up as buyers appear.

That scene should be read as a dealer-side worked example, not as a current allegation about a named firm or platform. The numbers and screen behaviour belong to the book’s 2010 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 reason the Pete example still teaches is that it strips the tree shake market maker interaction to its essentials. Pete is managing inventory and providing liquidity; he is not acting on company news. His actions can generate price signals that have nothing to do with the company’s underlying business. Investors who mistake a tree shake market maker manoeuvre for a company-level event are the ones most likely to act on noise rather than information.

Why A Tree Shake Works

A tree shake works because it attacks confidence. 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.

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 trying to find the other side of a trade.

The tree shake market maker tactic also works because it exploits the way many investors process information. Most private investors check prices before they check announcements. When they see a sharp move first and look for the cause second, the order of information is already backwards. Confirmation bias does the rest: once a story forms, people look for evidence that confirms it and discount what contradicts it. Understanding this changes your default response: the first question becomes “has an RNS been published?” rather than “what does this move mean?” That one shift in sequence removes the tree shake market maker’s main lever.

What Has Changed Since 2010

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

The FCA’s best-execution work frames execution quality around price, costs, speed and likelihood of execution for clients. Not every poor fill is suspicious, but execution is a real obligation, not a decorative phrase.

Retail investors now also have access to tools Pete’s contemporaries never had. Regulatory News Service feeds are available in near-real time through standard retail platforms. Level II data, once restricted to professional screens, is accessible at relatively low cost. FCA disclosures, directors’ dealings and significant shareholder notifications are all searchable online. None of this eliminates the information asymmetry that makes a tree shake market maker effective, but it narrows the gap. An investor who knows where to look can often distinguish a quote move driven by company news from one driven by order-book mechanics.

How To Read The Screen More Calmly

The practical response is to slow the decision down. Ask whether there is a company announcement, whether volume is unusual, whether the spread has widened, and whether the share is thinly traded enough for quotes to move around without much genuine information behind them.

That is not advice to trade through volatility. It is a way to avoid mistaking pressure for evidence. A useful discipline is to run through a short evidence checklist before you act: has an RNS been published? Has volume expanded significantly? Has the spread widened beyond its normal range? If none of these have shifted, you are most likely watching market structure, not company news. That short pause is precisely the lesson the tree shake market maker example is designed to teach. For background on how social media can amplify these patterns, our post on the evolution of the share ramp from ADVFN to Reddit covers the message-board layer that sits above the Level II screen today.

A Simple Example

Imagine a small company whose shares are usually quiet. The bid drops quickly, chat rooms start speculating, and a few holders sell because they fear bad news. Then the quote reverses and short-term buyers rush in. Nothing fundamental has changed, but the price action has created its own story.

The Street Smart lesson is to separate the story from the evidence. A genuine RNS, audited results or a confirmed takeover approach is information. A sudden quote move is a signal to investigate, not a reason to surrender judgement. For a wider view of how company news is shaped before it reaches investors, our post on how a 20% profit fall becomes a headline in a results announcement explains how the same numbers can look very different depending on who is doing the framing.

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. Market orders, hurried decisions and panic exits can hand control to someone with better information about the order book.

The sensible habit is to know why you own a share before the screen starts moving. If your reason is still intact, a sharp quote move deserves investigation. If your reason was only momentum or a message-board tip, the tree shake has already found the weak branch.

The related discipline is keeping a written record of why you own each position. When a tree shake market maker move happens, a written rationale stops you from unconsciously revising your thinking in real time. If the original thesis holds after the price shift, the right response is to pause and investigate rather than react to what the screen shows. That patience is not passivity: it is how you avoid becoming the exit liquidity that a tree shake market maker is designed to find.

In Plain English

A tree shake is the market’s way of testing who is nervous. The price move may be real, but the story you attach to it may be invented. Check the evidence before you act.