波卡（DOT）代幣經濟學

Polkadot's native token, DOT, is central to the network's security, governance, and resource allocation mechanisms. The token economics are designed to incentivize participation in the Nominated Proof-of-Stake (NPoS) consensus and manage the allocation of shared security resources (parachain slots). As of April 14, 2024, the total token supply has increased to approximately 1.43 billion DOT due to annual inflation, up from an initial total supply of 1.00 billion.

Issuance Mechanism

Polkadot employs an inflationary model, though it has recently transitioned to a fixed issuance rate, making it disinflationary as a proportion of the overall network issuance over time.

• Fixed Annual Issuance: The network issuance rate was recently reduced from a 10% year-on-year rate to a fixed issuance of 120 million DOT per year.
• Allocation of New DOT: This newly issued DOT is primarily used for two purposes:
  • Approximately 100 million DOT is allocated for staking rewards to compensate stakers and validators for securing the network.
  • The remainder funds the annual Treasury budget to support ecosystem activities.
• Inflationary Rewards Distribution: The amount of inflationary DOT directed toward stakers depends on the relationship between the "ideal staking rate" and the "system staking rate." When these two rates are equal, all new DOT is rewarded to stakers. Tokens not distributed to stakers are allocated to the project's Treasury. The ideal staking rate can vary between 45% to 75% based on the number of parachains that have acquired a lease through an auction.

Allocation Mechanism

The DOT token is allocated across various functions, with staking and parachain bonding representing the largest locked portions of the supply.

• Initial Supply: The initial total token supply was 1.00 billion DOT.
• Circulating Supply Dynamics: The introduction of parachain auctions significantly impacts the liquid supply. Projections based on early parachain launches suggested a major shift in distribution, with Parachain Bonds potentially accounting for 40% of the total supply, while the Circulating supply could drop from 30% to 15%, and Staking could decrease from 65% to 40%.
• Treasury Funding: The Polkadot Treasury is funded through:
  • A variable portion of inflationary DOT rewards.
  • 100% of DOT transaction fees.
  • An undisclosed portion of validator-slashing penalties.
  • Direct contributions from tokenholders.
• Token Concentration: As of April 14, 2024, the top 10 wallet addresses collectively hold approximately 301.60 million DOT (about 21.05% of the total token supply). Notably, major exchanges like Binance.com (~6.20%) and Kraken.com (~2.45%), along with the Treasury account (modlpy/trsry ~2.61%), represent significant holdings.

Usage and Incentive Mechanism

DOT serves four primary utility functions: network security, governance, parachain slot acquisition, and transaction fees.

Locking Mechanism and Unlocking Time

DOT tokens are locked for specific durations to fulfill network functions, primarily for securing parachain slots and enhancing governance participation.

The unlocking of bonded DOT from parachain slot leases occurs gradually over time, with significant amounts scheduled to be released corresponding to the expiration dates of the leases, such as around December 2025.