Transactions are conducted in ancient stock exchanges on the ground, called the trading floor for the exchange process, through the open shouting system. As for modern exchanges, they are conducted over the phone or the Internet, and all exchanges can be considered as auctions, in which buyers participate in competitive bidding, and sellers participate. In competitive orders during the trading day, however, some European exchanges used the periodic auction method, which works to conduct a periodic challenge once per trading day, and the first stock exchange was opened in Amsterdam in 1602.