The investor can choose to take a short position on a specific stock. When the price of such stock goes up, then the investor who sold the share will think that they were wrong in predicting that the price will go down. They will try to cover this short selling by re-purchasing it for any price. This in turn will push the stock price a bit up thereby increasing the losses that the investor might probably acquire. This situation is known as the short squeeze.

Caution: Short selling is a risky investment plan, which is done mainly by certified investors.
An investor should consult a savvy broker before trying to work with such investment.