Bitcoin crosses $10 for the first time on June 2, 2011, a 10x increase in under four months since reaching dollar parity in February. The first taste of exponential growth. A Gawker article about Silk Road published a few days earlier had driven a flood of new interest, and the price would continue its parabolic rise to over $31 by June 8. Early adopters who had mined or bought bitcoin for pennies were suddenly sitting on life-changing returns.
Wikipedia: History of Bitcoin