US30, also known as the Dow Jones Industrial Average (DJIA), is a stock market index that measures the performance of 30 large, publicly-owned companies listed on the New York Stock Exchange (NYSE) and the NASDAQ. The companies included in the index represent various sectors of the US economy such as technology, financial services, healthcare, and energy. The index is price-weighted, which means that stocks with higher prices have a greater influence on the index’s performance. It is one of the most widely followed stock market indices in the world and is often used as a barometer of the US stock market as a whole.