The discovery of the number zero is what led to a new trade good that improved the Gupta economy. The invention of zero by Indian mathematicians was a revolutionary concept that allowed for more advanced mathematics, including the development of the decimal system and the ability to represent numbers using a positional notation system. This innovation made it easier to conduct trade, commerce, and accounting, and allowed for more precise calculations of profits and losses. The use of zero in mathematics was a major contribution of Indian culture, and it helped to improve the economy of the Gupta Empire and beyond.