A more thorough explanation:

Definition: Speculation is when someone buys or sells something with the hope of making a profit from changes in its price. It can also refer to the act of making guesses or theories about things that are not known for sure.

Examples:

• He made a lot of money through speculation in the stock market.
• There was a lot of speculation in the media about who would win the election.
• People often engage in speculation about the future of technology.

The first example shows how someone can make money by buying and selling stocks based on their predictions of how the market will change. The second example shows how speculation can be used to make guesses about current events. The third example shows how speculation can be used to make predictions about the future.