When your initial balance is doubled, the Accelerator Coin becomes available and appears in the "History" box within the trading room. To use it, decide when you want to double your current balance again. At that moment, access the "History" box and select the "Coins" tab. You will be prompted to flip the coin by choosing either heads or tails. If the coin lands on your selected side, the doubling feature is applied to your balance, allowing you to significantly boost your profits.