The Big Dictionary of Dreams

by Martha Clarke
Betting in dreams means you are willing to take risks. The cause may come from a situation in real life. Maybe you are willing to bet blindly for a path in the future. In this case, you should weigh the items involved in this circumstance and calmly choose the choice you deem best. As for recreational gambling, there are people who believe in the premonitory power of dreams and have acted—in real life—as those dreams suggested. This does not mean you must depend solely on oneiric chance; no doubt you may suffer big economic losses.

The meaning of this image must be reversed.

If you dream of winning a bet, you will lose and vice versa.

The Complete Guide to Interpreting Your Dreams

by Stearn Robinson - Tom Corbett
The wind of change is blowing in your direction if you dreamed of betting yourself; if you observed others doing the betting, look sharp for mischievous competitors in business and/or love affairs.

See also Gambling, Money, etc.

New American Dream Dictionary

by Joan Seaman - Tom Philbin
1. A risk is being undertaken; use caution in business affairs.

2. Good luck is in the offing (to win).

3. To gamble with some­thing held dear—possibly a relationship, often an aspect of personality or reputation.