ポルカドット (DOT) トケノミクス

Polkadot’s native token, DOT, is the central utility and governance asset of the network. Its economic model is designed to secure the relay chain, facilitate interoperability through parachains, and provide a robust framework for decentralized governance. As of April 14, 2024, the total token supply reached approximately 1.43 billion DOT.

Issuance Mechanism

Polkadot originally launched with a total supply of 1.00 billion DOT. The network utilizes an inflationary issuance model to incentivize security and fund ecosystem growth.

• Inflationary Model: Initially, the network maintained a 10% year-on-year token issuance rate. However, recent governance updates have transitioned the network toward a fixed issuance rate of 120 million DOT per year. This change makes DOT disinflationary, as the fixed issuance becomes a smaller percentage of the total supply over time.
• Distribution of New Issuance: Approximately 100 million DOT of the annual issuance is earmarked for staking rewards to secure the network. The remaining portion is directed to the Polkadot Treasury to fund ecosystem development.
• Burn Mechanism: To offset inflation, Polkadot employs a burn mechanism where 1% of available treasury funds are burned at the end of every 24-day spend period. Additionally, 100% of transaction fees and a portion of validator slashing penalties are directed to the treasury, where they may eventually be subject to these burns.

Allocation Mechanism

The initial allocation of DOT was distributed through public and private sales, as well as allocations to the founding entities.

Usage and Incentive Mechanism

DOT serves four primary functions within the ecosystem:

1. Staking and Security

Polkadot uses a Nominated Proof-of-Stake (NPoS) consensus mechanism.

• Validators: Run nodes to verify parachain blocks and produce Relay Chain blocks. They earn rewards based on "Era Points" (earned through payable actions like issuing validity statements) rather than their total stake.
• Nominators: Tokenholders who back validators with their DOT. They receive a pro-rata share of validator rewards minus commissions.
• Slashing: Validators who behave maliciously or remain offline lose a portion of their staked DOT, which serves as a strong economic disincentive against bad behavior.

2. Governance

DOT holders have full control over the protocol through OpenGov.

• Proposals: Users must provide a "submission deposit" (typically 1 DOT) to create a proposal.
• Voting Weight: Voting power is determined by the amount of DOT held and the length of time the user is willing to lock those tokens (conviction voting).
• Delegation: Tokenholders can delegate their voting power to other accounts.

3. Parachain Slot Auctions

To connect to the Relay Chain, projects must secure a parachain slot through a candle auction.

• Bidding: Projects bid DOT to lease a slot for up to 96 weeks.
• Crowdloans: Projects can solicit DOT from the community to fund their bid. Contributors' DOT is locked for the duration of the lease, and they often receive native project tokens as an incentive.

4. Transaction Fees and Operations

DOT is used as a medium of exchange and to pay for network transaction fees. It is also required for creating accounts and registering on-chain identities.

Locking Mechanism and Unlocking Time

Locking is a fundamental part of Polkadot's security and governance.

• Staking Unbonding: When a user stops staking, their DOT enters an unbonding period. While the standard wait time has historically been 28 days, the 2025 roadmap includes plans for "Fast Unlocking" to reduce this duration and improve user experience.
• Governance Locks: Users can increase their voting weight by locking DOT. For example, locking tokens for 32 periods (896 days) provides a 6x multiplier on voting weight.
• Parachain Bonds: DOT used to secure a parachain slot (whether self-funded or via crowdloan) is locked for the entire 96-week lease duration.
• Unlocking Schedule: Bonded DOT is released gradually as leases expire. A significant cumulative unlock of approximately 8 million DOT is projected to be completed by May 2026 as various parachain batches reach the end of their terms.