As Bitcoin's August surge reignites old ambitions, Coinbase CEO Brian Armstrong has offered a revised vision of the cryptocurrency's future — one measured not in millions, but in the quieter arithmetic of sustained, hard-won growth. His projection of $300,000 to $400,000 by 2030 is grounded in Bitcoin's own turbulent history, a record that includes both extraordinary gains and devastating losses. The forecast is as much a reckoning with what has changed as it is a statement of belief in what endures.