Price goes up.

The whole stake is at risk, and the gain has no ceiling.

Price goes up, but not enormously.

Cheaper than a plain up-bet because the winnings stop at the higher price.

Price goes up, funded by taking on the downside.

Costs little or nothing up front, but a fall costs you real money — the loss is not capped.

Price drifts up but stops before the higher price.

Cheap, and can even pay you to open — but a violent rally loses without limit.