#BinancePizza refers to the famous "Bitcoin Pizza Day", which celebrates the first recorded transaction of Bitcoin in which a person used the cryptocurrency to buy something in the real world. This transaction took place on May 22, 2010, when a programmer named Laszlo Hanyecz bought two pizzas for 10,000 BTC. At the time, this was a significant amount of Bitcoin, but nowadays, those pizzas are considered one of the most iconic purchases in the history of cryptocurrencies.