Financial Betting is arguably a litle different to normal betting, in that financial instruments should follow patterns or react to certain market conditions.
If you bet on a horse, you are playing odds - though one might argue if you research the horses, their history, their trainers and the jockeys - you might have a much stronger chance of your horse coming in in a winning position. If you play roulette in a casino - you are simply playing statistics.
With financial betting you are generally betting either on a value at a certain period of time, or more often on the movement a financial instrument will make - up or down.
For this reason many people place financial betting in a category of investment, rather than just betting. It can be argued that an informed investor can guess the movement of a share or currency, and therefore consistently turn a profit. There are also tools such as 'stop losses' that can be used to reduce the risk of serious loss.
However, if it is true that some investors can consistenly turn a profit with financial betting, it is also true that many more lose at financial betting than win. Approached logically and un-emotionally - financial betting can be part of a balanced investment strategy - however where money is involved, many of us fail to be un-emotional, and apply logic to our betting.