The tactics used by Americans are very common. When they buy up all the Bitcoin on the market, and they hold all the Bitcoin, the price fluctuations are dictated by them. That's why you see MicroStrategy buying at 30,000, daring to buy at over 60,000, and daring to buy at over 100,000. Even if they buy at 500,000 each, as long as the overall trend continues to push Bitcoin up, they can buy without hesitation.