what is the main reason of pre match odds movements

[travel&bet]

these days i'm observing the tennis markets before kick off and i'm trying to make some logical explanation why the odds move up or down and who moves them.I noticed that sometimes arbitrage bettors move the market because they have opportunity to make some money.In markets where there are short priced favs i see that a lot of layers move up the market cause they have small liability and can use huge stakes.But actually i still can't understand clearly are the odds moving because of the people bet's in the bookies or because of some information.I saw movement from 1.80 to 2.10 just for 20 hours.I'll be glad if someone share some opinion.Cheers!

[Iron]

The short answer is that markets move because market participants disagree on what the price should be, as well as moving in response to new incoming information.

Let's say that 80% of the market thinks that a horse is priced too low. Layers metaphorically shoving each other out of the way by offering better prices to backers than the next guy (rather than just patiently leaving their money in the queue and risking missing the boat) will probably cause the price to drift.

Jeff

[travel&bet]

i do agree.wimbledon was far easy to predict where the odds are going to but atp tournaments seem to be much more different.I noticed that favs these days tend to drift up..i guess this is mainly because people think big players are tired and the time of the wannabes has come : )