> in sports from what I understand the odds are determined by the amount gambled on either side This is incorrect. This is what applies in a totalizator market

> in sports from what I understand the odds are determined by the amount gambled on either side This is incorrect. This is what applies in a totalizator market like some racing betting agencies. They take the pool of money (eg for a win) and deduct a fixed fee before paying out to the winning bet. The "odds" there are determined by which competitor the market thinks is most likely to win. But bookmakers actually provide odds based on their own assessments. They are taking the "other side" of the bet and can suffer losses. And yes, there are bookmakers that will take bets on almost anything. They do it the same as any risk takers, by researching the probabilities. People bet on political outcomes, sports outcomes, all sorts of different real world events.