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. Originally launched with a total supply of 1.00 billion, the supply has grown to approximately 1.43 billion as of April 2024 due to its inflationary design. The token economics are structured to secure the network through staking, facilitate resource allocation via parachain auctions, and empower decentralized governance.

Issuance Mechanism

Polkadot historically utilized a variable inflation model, but recent governance decisions have shifted the network toward a more predictable issuance schedule.

• Fixed Issuance Rate: The network has transitioned to a fixed issuance rate of 120 million DOT per year. This change makes DOT disinflationary, as the fixed annual issuance becomes a smaller percentage of the total supply over time.
• Distribution of New Tokens: Of the 120 million annual DOT issued, approximately 100 million DOT is earmarked for staking rewards to secure the network. The remaining 20 million DOT is directed to the Polkadot Treasury to fund ecosystem development.
• Inflationary Dynamics: Prior to this shift, the network targeted an "ideal staking rate" (typically between 45% and 75%). If the actual staking rate deviated from this ideal, a portion of the inflation was diverted from stakers to the Treasury.

Allocation Mechanism

The initial allocation of DOT was designed to distribute ownership across the community, early backers, and the founding entities.

Usage and Incentive Mechanism

DOT serves four primary functions within the ecosystem:

1. Staking (NPoS): Polkadot uses a Nominated Proof-of-Stake (NPoS) mechanism. Validators earn "Era Points" for performing payable actions (e.g., issuing validity statements). Rewards are distributed pro-rata based on these points rather than total stake.
2. Governance: DOT holders participate in OpenGov, Polkadot’s on-chain governance system. Tokens are used for submission deposits (1 DOT) and decision deposits to advance proposals through 15 different governance "tracks."
3. Parachain Bonding: To secure a dedicated execution slot (parachain), entities must bond DOT. This is done through candle auctions where the highest bidder wins the right to use the slot.
4. Transaction Fees: DOT is the universal fee token for the Relay Chain and is increasingly being integrated as a fee token for various Rollups and parachains.

Locking Mechanism

Locking is a fundamental security and commitment feature in Polkadot, applied in several contexts:

• Staking Lock: To participate in consensus, validators and nominators must bond their DOT. This capital is at risk of "slashing" if the validator acts maliciously or remains offline.
• Governance Conviction Locking: Users can increase their voting power by locking DOT for longer durations. For example, locking tokens for 32 periods (896 days) provides a 6x multiplier on voting weight.
• Parachain Slot Bonding: DOT used to win a parachain auction is locked for the entire duration of the lease.
• Crowdloans: Community members can lock their DOT in support of a project’s parachain bid. These tokens are held by the Relay Chain, not the project team, ensuring a trustless process.

Unlocking Time and Schedule

The unlocking of DOT is governed by specific protocol rules and lease durations:

• Staking Unbonding: Historically, the unbonding period for staked DOT has been 28 days. However, the 2025 roadmap includes plans for "Fast Unlocking" to reduce this wait time and improve user experience.
• Parachain Lease Duration: DOT bonded for a parachain slot is locked for a maximum of 96 weeks (approximately two years).
• Unlocking Schedule: A significant amount of DOT is scheduled to be released as early leases expire. For instance, a cumulative total of approximately 8 million bonded DOT is projected to be unlocked through various expirations by May 2026, with a major unlocking event expected around December 2025.
• Treasury Burns: The Treasury includes a deflationary pressure where 1% of available funds are burned at the end of every 24-day spend period if they remain unspent.