About Polkadot
Polkadot is a network designed to let separate blockchains pass messages and share security through a central relay chain. Its native token, DOT, is used for staking and for governance votes.
Coretime, and where new DOT comes from
A chain used to win its place on Polkadot by bidding in an auction and locking DOT, the network’s own token, for the duration of the slot. Auctions ran until Agile Coretime launched on 19 September 2024, when ongoing ones were cancelled and existing leases were migrated across automatically. Blockspace is now bought as coretime: in bulk, as a fixed month-long allocation that a busy chain renews, or on demand, bid for in near real time to validate a single block.
New DOT is created rather than mined, and that model changed in November 2024. Supply now expands by a fixed 120 million DOT a year, of which 85 per cent goes to stakers and 15 per cent to the treasury. The wiki describes the change as a move from exponential growth to linear: a fixed number of new tokens each year, against a total that keeps rising. Some of it is destroyed again, including unspent treasury funds and the proceeds of coretime sales, so the net addition is smaller than the gross one. That rate can be changed by on-chain governance, and it has been.
Anyone can start a referendum, at any time and as often as they wish. That is how Polkadot OpenGov works, and DOT holders vote on each one with their tokens, weighted by how long they agree to lock them. It replaced an earlier arrangement built around a council and a technical committee.
The coretime buys into one validator set that secures every connected chain, so a new chain never has to recruit validators of its own. That arrangement runs in both directions, and the second direction is the cost. Connected chains share state with the central chain, so if that chain has to revert, they revert with it.
Longer read: How Polkadot coretime and shared security work. Polkadot retired parachain slot auctions and replaced them with coretime, a purchase of validation time on the relay chain - and shared security is a commitment that runs in both directions.
See more prices on the crypto in AUD hub, and how this figure is struck on the methodology page.