Price Calculation

The CoolDEX uses a constant product market maker (CPMM) formula for price calculations.

Constant Product Formula

The core formula for the CoolDEX is:

k = x * y

Where:

• x is the amount of token X in the pool

• y is the amount of token Y in the pool

• k is a constant that must be maintained during trades

This formula ensures that the product of the two token reserves remains constant, which creates a hyperbolic price curve.

Swap Base In Calculation

When a user specifies the input amount for a swap, the output amount is calculated as:

amount_out = (pool_out * amount_in) / (pool_in + amount_in)

Where:

• pool_out is the amount of output token in the pool

• pool_in is the amount of input token in the pool

• amount_in is the specified input amount

Example Calculation

Let's say:

• Pool has 1,000,000 TOKEN and 1,000 SOL

• User wants to swap 10 SOL for TOKEN

The calculation would be:

amount_out = (1,000,000 * 10) / (1,000 + 10)
amount_out = 10,000,000 / 1,010
amount_out ≈ 9,900.99 TOKEN

Swap Base Out Calculation

When a user specifies the output amount for a swap, the required input amount is calculated as:

amount_in = (pool_in * amount_out) / (pool_out - amount_out)

Where:

• pool_in is the amount of input token in the pool

• pool_out is the amount of output token in the pool

• amount_out is the specified output amount

Example Calculation

Let's say:

• Pool has 1,000,000 TOKEN and 1,000 SOL

• User wants to receive exactly 10,000 TOKEN

The calculation would be:

amount_in = (1,000 * 10,000) / (1,000,000 - 10,000)
amount_in = 10,000,000 / 990,000
amount_in ≈ 10.10 SOL

Fee Calculation

Fees are applied to the swap amounts. The exact fee calculation depends on the token type:

Standard Tokens

For standard (non-SC Bonding Curve) tokens, a simple fee is applied:

fee_amount = amount_in * fee_numerator / fee_denominator
amount_in_after_fee = amount_in - fee_amount

SC Bonding Curve Tokens

For SC Bonding Curve tokens, the fee calculation is more complex and depends on the token's specific parameters:

1. For selling tokens (Coin2PC):

   taxable_amount = amount_in * swap_fee_numerator * (cooldex_team_fee_wsol_fee_denominator - cooldex_team_fee_wsol_fee_numerator) / (swap_fee_denominator * cooldex_team_fee_wsol_fee_denominator)
   amount_to_burn = taxable_amount * burn_rate / CURVE_BURN_RATE_DENOMINATOR
   cult_token = (taxable_amount - amount_to_burn) / 2

2. For buying tokens (PC2Coin):

   taxable_amount = amount_in * swap_fee_numerator / swap_fee_denominator
   platform_tax = taxable_amount * cooldex_team_fee_wsol_fee_numerator / cooldex_team_fee_wsol_fee_denominator
   cult_wsol = (taxable_amount - platform_tax) * (CURVE_BURN_RATE_DENOMINATOR - burn_rate) / (2 * CURVE_BURN_RATE_DENOMINATOR)

LP Token Calculation

Adding Liquidity

When adding liquidity, the amount of LP tokens minted is proportional to the share of the pool being added:

mint_lp_amount = (deposit_amount / total_amount) * total_lp_supply

Where:

• deposit_amount is the amount of the base token being deposited

• total_amount is the total amount of that token in the pool

• total_lp_supply is the current total supply of LP tokens

Removing Liquidity

When removing liquidity, the amounts of tokens received are proportional to the share of LP tokens being burned:

token_amount = (lp_amount / total_lp_supply) * total_token_amount

Where:

• lp_amount is the amount of LP tokens being burned

• total_lp_supply is the current total supply of LP tokens

• total_token_amount is the total amount of the token in the pool