What Causes Pre-Race Market Movements?

The public opinion, both professional and recreational, drives market movements. For every selection in a sporting event an opinion is made up of optimistic Backers and pessimistic Layers. As the market forms and we get closer to the start of the event (e.g. the race), the public opinion reaches a consensus. At this point the odds are at their most accurate and the phenomenon referred to as the “Wisdom of Crowds” has played it’s part.

In this article I explore the factors that may consciously or unconsciously form the public opinion in the lead up to the race.


Statistics & Form

Many punters are heavily influenced by facts surrounding the race. Some influential items of data are:

  • Horse-specific: How the age, sex, fitness, and weight-over-distance ability compares with the other horses
  • Form: For example, the Jockey/Trainer strike rates
  • Race type: How horses are likely to perform on a specific race type based on their track record
  • Weather conditions: How the horses typically perform under the current weather conditions.

The bettor often considers such factors, and deliberately or subconsciously assign a level of importance (“a weighting”) that this has on his betting selections. Unless of course the selection is made completely at random!

Many bettors consider weather conditions to be influential and relevant. So for example he may try to base his selection(s) heavily around horses that relish a wet, muddy track and those that despise it. The same logic applies for a dry, stiff track.

Selection methods using past data can be as basic as circling horses from the Racing Post, to analysing thousands data items in Excel. And then there’s even more complex data mining techniques, too.


Outside Influences

Odds are moved by factors influencing large groups of people:

  • Commentators: The opinion of a racing expert may affect the volume of money placed on a horse. Especially around the time the opinion was broadcast.
  • Tipsters: Professional tipsters operate with a large audience and reach out via email, phone or social media. Hundreds or thousands of people may place bets after receiving a tip, typically within a short timeframe, causing market movements to occur.
  • Insider knowledge: A taboo topic in Horse Racing, and it’s undeniably responsible in initiating many large market movements. Big money stakes backing horses at odds well above the fair value helps bring the market closer to accuracy. Following the large stakes, the odds begin to reflect a more accurate probability of the horse winning the race.


The Bookmaker

We generally associate market movements with activity on the betting exchange. But the Bookmakers (like Pinnacle) also influence the public opinion on a large scale. For a punter that never checks the exchange odds, their frame of reference is narrowed to the Bookmaker’s odds. For example:

  • Opening odds: The odds initially posted by the bookmaker are not particularly accurate, but give the public a basis to build the market, and their opinions, around. There are opportunities for bettor to pick off value in the hours leading up to the race before the odds eventually form with greater precision.
  • Increased/Reduced odds: Leading on from the previous point on the opening odds, bookmakers increase/reduce odds (and therefore risk) when horses are heavily backed. As a result, the public now has a new industry price which is higher/lower than it was before. This reshapes the opinions held by a large section of bettors.

In addition to shaping public opinion with their odds, the Bookmakers are also likely to reduce their risk by laying off horses where they’ve accepted a high stake (i.e. high risk). Given the likelihood of this being a substantial volume, the exchange odds will be impacted, and consequently so will the opinion of many others in the public.

Pinnacle Sports Review



Human Factors

Human factors influence market movements. As irrational as it can often be, our nature leads us to form opinions — and often this creates value betting opportunities. The most common human factors which influence Horse Racing markets are:

  • Superstition & Random choice: Horses are chosen for the most peculiar reasons, like the name, colour, or even just a “feeling”. The choice isn’t necessarily well founded.
  • Herd Mentality: Odds rise or fall as a result of momentum. Once the market has moved in one direction many bettors jump on the back of it and push the odds further in the same direction.
  • Pre-race Observations: A horse’s equipment or appearance in the parade ring plays a part. Its gait, sweating, or restiveness can influence our confidence, and this goes for any sporting event: think about watching football players as they stand in the tunnel before a match. The public observes signs of strength or weakness, as tenuous as they may be.



Horses declared non-runners create waves in the market. I find this the most interesting of all the factors as you can observe and analyse the changes in the market following an announcement.

In the following graph I show the impact of a non-runner on the favourite in a race starting at 13:10.

Market Movements for Nonrunner

  • “NR” shows the point where our sources first alerted us of the NonRunner at 07:05:29 AM
  • By 07:40 AM the odds moved from 3.25 down to 3.0 (-8% change)
  • The odds rose to 3.2 by 07:50 before hitting an all-time low of 2.84 at 08:20 AM (-12.6% move since the NR)
The volatility is high, caused by the increase in activity due to the Non Runner. When a sudden event like this occurs, the market reacts and creates a difference in opinion which in this case lasted for just over an hour before stabilising and reaching a consensus.

To find out more on how the public opinion shapes the fair odds of a sporting outcome, please read my post on the Wisdom of The Crowds theory for betting.


Further Reading:

The Accuracy & Significance Of SP Odds

Drifters & Steamers — The Risers & Fallers Of Betting Markets

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Tobyvirginiac mendozaTom Davies Recent comment authors
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Tom Davies
Tom Davies

Yes, i think that some pretty irrational things cause swings in the market. Sometimes for a short period of time it goes into a frenzy… that’s where I’ve capitalised the most. The uncertainty of other gamblers on the market is where you get panic buys/sells. Plenty of pro traders are quick to the punch on those types of scenarios, though. Any tips for getting there quick?


Getting there quick is key. – If you’re not already, then it’s a good idea to use a trading tool like Geeks Toy. This will speed up your bet placement, particularly with it’s ‘1-click’ feature: http://punter2pro.com/geekstoy – You could also try to ‘get on’ value odds before the crowd using a good race analyser. I don’t recommend using popular data sources/predictors like Racing Post. I prefer less popular sources, such as ‘Before The Off’. – If you already have some form of strategy then it makes sense to automate it. For this I recommending trialling BF Bot Manager, as it… Read more »

virginiac mendoza
virginiac mendoza

Applies to all sports right?
Commentators/pundits have far too much influence on the way people think about the game.


Every sport. Especially Football, where the fans seem to be most heavily influenced by opinions.