Bitcoin Pizza refers to the infamous moment in 2010 when a programmer named Laszlo Hanyecz bought two large pizzas for 10,000 BTC, worth about $41 at the time. It's like the crypto equivalent of trading a Picasso for a pack of gum.
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"The Bitcoin Pizza transaction is a classic example of how much the value of BTC has grown over the years, those pizzas would be worth over $300 million today!"
"Every year on May 22, Bitcoiners celebrate 'Bitcoin Pizza Day' to commemorate Laszlo's legendary purchase and the early days of Bitcoin adoption."