Hot issue is a new issue of securities which trades at an immediate premium to its offering price in the secondary market.
Applying "Hot Issue" to Securities Exams:
When a new issue of common stock is being sold to investors during an IPO is in high demand its price may increase dramatically in the secondary market. A hot issue is one that trades at an immediate premium to its offering price on the first day of trading in the marketplace. The higher the demand for the issue – the greater the premium or increase in price.