Tokenomics.

Every coin launched on zkBNB is created the same way: a fixed supply, sold on a public bonding curve, with no team allocation, no presale and no way to mint more.

$ZKBNB, the rootstock token, is the exception. It was launched on Flap, not on zkBNB, and follows Flap's rules. See $ZKBNB, the rootstock token below.

Supply

• 1,000,000,000 tokens, 18 decimals, all minted once to the Launchpad contract when the coin is launched.
• The coin contract has no mint function. Supply can only go down.
• The deployer gets nothing for free. A deployer who wants tokens buys them on the curve like everyone else, and pays the same 2.00% fee.

The bonding curve

The price comes from a constant-product curve with virtual reserves, the shape pump.fun uses, scaled to BNB:

VIRTUAL_BNB    = 4 BNB
VIRTUAL_TOKENS = 1,073,000,000
k              = (VIRTUAL_BNB + BNB raised) × (VIRTUAL_TOKENS − tokens sold)
price          = (VIRTUAL_BNB + BNB raised)² ÷ k

The price rises about 14.7 times from the first buy to the last. Market cap below is price × 1,000,000,000.

BNB raised is net of the 2.00% fee. Buying out the whole curve takes about 11.57 BNB including fees.

Graduation

When the last of the 793,100,000 curve tokens is sold, the coin graduates in the same transaction:

1. The Launchpad creates the PancakeSwap V2 pair, or reuses one that someone created early.
2. It adds every token it still holds (the 206,900,000 reserved) and all the BNB raised (about 11.33 BNB) as liquidity.
3. The LP tokens are sent to the dead address. The liquidity is locked for good: nobody can pull it.

The pool opens at the curve's last price (about 0.0000000548 BNB), so there is no jump at graduation. If someone seeded the pair before graduation, the Launchpad rebalances it first: an early seed can only lower the opening price, never take the raised BNB. From then on, every swap with the pair leaves 2% of the tokens in the coin contract. Those tokens are swapped to BNB and split exactly like a curve fee. See Fees.

Burns

Tokens leave the supply in two ways, both permanent:

• Harvests. Burning coins into the roots destroys them, which is how a holder collects their share of the coin's BNB.
• $ZKBNB buybacks. The rootstock pot buys $ZKBNB and sends all of it to the dead address.

totalSupply() on each zkBNB coin already excludes burned tokens, so the number BscScan shows is the live supply. $ZKBNB is a Flap token: what the buybacks remove sits at 0x…dEaD, so subtract that balance from its totalSupply().

$ZKBNB, the rootstock token

$ZKBNB is the platform token. It is not a zkBNB coin: the operator launched it on Flap, another launchpad on BNB Smart Chain, as a Flap tax token paired with Binance-Peg ZEC. Its contract, curve, tax and dividends are Flap's code, not zkBNB's.

• Where it trades. First on Flap's bonding curve, priced in ZEC. You can pay with BNB there; Flap swaps it to ZEC for you. When the curve fills, Flap moves it to a PancakeSwap V2 pair against ZEC.
• A 2% tax, both ways. 2% on buys and 2% on sells, for the life of the token. Flap collects it, takes its own share (below) and splits the rest in two: half to the creator wallet, half to $ZKBNB holders as dividends paid in ZEC. Dividends go to holders above a minimum balance set at launch; pools, the dead address and Flap's own contracts earn none.
• Flap's fees. Per Flap's docs: 1% on every bonding-curve trade on BNB Chain (the tax is added on top, so a curve trade pays 3% in all), and up to 0.3% of trade volume for tax tokens. Flap also pays a commission from the tax to the token's commission receiver, here the creator wallet: 3% of the tax after Flap's fee, at a 2% tax rate. These are Flap's figures and Flap can publish new ones. Check docs.flap.sh.
• Demand from the whole platform. 0.50% of every trade on every zkBNB coin goes into the rootstock pot. The FlapBuyback contract spends it on $ZKBNB, through Flap while it is on the curve and through PancakeSwap after, and sends every token to the dead address. A buyback is a buy like any other: it pays the 2% tax and Flap's fees. See the flywheel.
• No zkBNB fee of its own. $ZKBNB does not pay zkBNB's 2.00% fee, so it has no roots and no deployer's choice. Its holders are paid by Flap's dividend contract, not by zkBNB.

The $ZKBNB and FlapBuyback addresses are listed under Addresses. Check them there before you buy: anyone can launch a token with any name, on Flap or here, and a name proves nothing.

On BNB testnet there is no Flap token. A test $ZKBNB runs on zkBNB's own curve so the buyback can be tried end to end.

What the operator earns

The operator's income is public. The zkBNB parts are fixed in the contracts; the $ZKBNB parts are set by Flap:

• 0.20% of every trade on every zkBNB coin (10% of the fee; the contract caps this at 20% of the fee).
• As the $ZKBNB creator wallet: half of the 2% $ZKBNB tax after Flap's fee, paid in ZEC, plus Flap's commission on the tax. Buybacks pay this tax too.
• The launch fee (0.005 BNB per token) and the cause registration fee (0.002 BNB).

The operator cannot take roots, reward pots, ring pots or shielded notes, and cannot mint tokens. See Trust model.