Buy Polkadot

Polkadot is a network designed to let many separate blockchains run alongside one another and share a single set of security guarantees, rather than each one having to defend itself. DOT is the cryptocurrency that pays for activity on that network, secures it through staking and decides how it changes.

The network has been substantially rebuilt since 2024, and the things people most often repeat about it, such as two year parachain slot auctions and an uncapped ten percent annual inflation rate, are no longer how it works. Our guide to blockchain covers the basics, and our guide to blockchain layers explains where a network like Polkadot sits relative to the others.

What problem is Polkadot trying to solve?

A single blockchain has to be everything to everyone. It sets one fee market, one set of rules and one performance ceiling, and every application on it competes for the same space.

Polkadot's answer is to let each project run its own chain, tuned to what that project actually does, while renting security and settlement from a shared base. A chain connected to Polkadot does not need to recruit its own validators or fund its own security budget, and it can pass messages to the other chains connected to the same base.

That is the design goal. Whether it has worked commercially is a separate question, and the risks section below deals with it directly.

How Polkadot works now

The part that has changed most is how a project gets access to the network.

Originally a project had to win a slot at auction and lock DOT for up to two years to keep it, often by crowdfunding that DOT from supporters. That model has been retired. Polkadot now sells coretime: computing capacity bought in bulk or on demand, in flexible amounts and for flexible periods, closer to buying capacity from a cloud provider than to winning a long lease. The project's own framing for this is Polkadot Cloud.

Alongside it, elastic scaling allows a single chain to use more than one core at once when it needs the throughput, instead of being held to one block per core per cycle.

For someone buying DOT, the practical consequence is that the old story about scarce slots creating locked up demand for the token no longer applies. Access is cheaper and more flexible, which is better for developers building on Polkadot and removes a mechanism that previously forced DOT to be bought and held.

What is Polkadot Hub?

In November 2025 Polkadot moved balances, staking and governance off the relay chain and onto Asset Hub, which is now presented as Polkadot Hub. The relay chain still provides consensus and security underneath. Almost everything an ordinary holder touches now happens on the Hub.

Smart contracts went live on Polkadot Hub in early 2026, through an execution environment called Revive that runs Ethereum compatible Solidity contracts alongside PolkaVM, a higher performance engine built on the RISC-V instruction set. In plain terms, developers can deploy the same Solidity contracts they write for Ethereum onto Polkadot using familiar tools. The Polkadot Hub documentation sets out what is supported.

This is a real change of direction. For most of its life Polkadot did not put smart contracts at its center. It put chains there. It now has both.

What is JAM?

JAM, the Join-Accumulate Machine, is the proposed successor to the relay chain: a more general purpose base layer that treats the network as a shared trustless computer rather than as a coordinator for a fixed set of chains. It is specified in the Gray Paper, and the Web3 Foundation has run an implementer's prize to encourage independent teams to build competing versions of it.

Two things to be clear about. JAM is not live on the main network, and no firm launch date has been committed to, so it belongs in the column marked ambition rather than infrastructure. And JAM is not a new token. A DOT holder does not need to swap, bridge or claim anything because of it, and any site offering to migrate your DOT into something else is a scam.

What is DOT used for?

Security. DOT is staked, directly or through a nomination pool, to select and back the validators that secure the network. Governance. DOT votes on referenda that change the protocol, spend from the treasury and approve upgrades. Fees. Transactions and smart contract execution are paid for in DOT. Coretime. The market for access to the network's capacity is denominated in DOT.

Has DOT's supply changed?

Yes, and this is the most important correction to any older article about the asset.

DOT originally had no maximum supply and issued new tokens at roughly ten percent a year. In September 2025 Polkadot's governance passed referendum 1710, which set a hard maximum of 2.1 billion DOT and replaced the flat rate with a stepped schedule. A fixed share of the remaining distance to the cap is issued, and the step is recalculated every two years, so issuance falls over time and approaches the cap without reaching it for a very long time. The first step took effect in March 2026.

Two caveats are worth holding onto. A cap is not the same thing as scarcity, because new DOT continues to be created under this schedule for generations. And a change to supply does not create demand. It removes a headwind rather than supplying a reason to own the asset.

How does staking DOT work?

Polkadot uses nominated proof of stake. Validators run the nodes that produce and finalize blocks. Holders who do not want to run a validator can nominate a set of validators, or join a nomination pool with other holders, and share in the rewards those nominations earn. Since the 2025 migration, staking and reward claims happen on Polkadot Hub. Our guide to crypto staking explains the general model.

The rules changed materially in 2026. Validators are now required to post a minimum amount of their own DOT as self stake, and that self stake carries the slashing risk. In exchange, nominated stake is no longer slashed when a validator misbehaves, and the unbonding period was shortened from twenty eight days to a period measured in hours rather than weeks. Staked DOT is still locked while it is bonded, and rewards still depend on the validators you back staying online and behaving.

CoinJar does not stake DOT on your behalf. DOT held in a CoinJar account is not nominated to any validator, does not earn staking rewards and is not subject to any bonding or unbonding period.

Who controls Polkadot?

Governance is on chain, through a system called OpenGov that replaced the earlier council and technical committee. Any DOT holder can vote on a referendum directly or delegate their vote to someone else, and voting weight can be increased by locking tokens for longer, a mechanism called conviction voting. Different kinds of proposal run on different tracks with different thresholds and timelines. Treasury spending is decided the same way.

That makes Polkadot's decision making genuinely more open than most large networks, and also slower and noisier. Parity Technologies builds much of the core software and the Web3 Foundation funds and supports the ecosystem, but neither can change the protocol on its own. Gavin Wood, who co-founded Ethereum before starting Polkadot, remains the project's leading architect. The official Polkadot site is the starting point for current governance and network information.

What are the risks of holding DOT?

Execution risk. Much of the case for DOT rests on delivery that has not happened yet, including JAM and broader adoption of Polkadot Hub. Roadmaps in this sector slip routinely, and Polkadot's have. A moving target. The network has been redesigned repeatedly: slot auctions to coretime, relay chain to Hub, and now a proposed successor to the relay chain itself. Constant change is a sign of active development, and it also makes the network harder to assess and harder for developers to commit to. Ecosystem attrition. Projects including Centrifuge, Manta and Phala have left or wound down their Polkadot deployments, generally in favor of Ethereum and its layer twos. Reasons vary by project, but the pattern is documented and it matters. Competition. Polkadot competes with Ethereum's layer two ecosystem, with Cosmos and other application chain models, and with high throughput networks that offer developers a larger existing user base and deeper liquidity. Governance and treasury controversy. Polkadot's treasury spending, particularly on marketing in 2024, drew sustained criticism from within its own community, and there have been public disputes with contributors over payment. On chain governance means those arguments happen in public, which is healthier than the alternative and also unflattering. Continued issuance. New DOT is still being created under the stepped schedule. The rate is much lower than it was, but it is not zero. Staking risk. Bonded DOT is locked, validators can go offline or misbehave, and nomination pools introduce their own dependencies. Staking is not a savings account. Bridge and wrapped asset risk. Representations of DOT on other networks depend on the bridge or custodian behind them, and bridges have repeatedly been exploited across the industry. Volatility. DOT is not a stablecoin. Its value moves sharply and can fall a very long way and stay there. No government compensation. Digital assets are not deposits. They are not insured by the FDIC and they are not protected by SIPC. If you lose value, there is no compensation scheme to fall back on.

Buying DOT with US dollars on CoinJar

CoinJar has operated since 2013 and lists DOT against US dollars, so you can buy, sell and hold it without converting through another cryptocurrency first. Current charges are on our fees page, and live US dollar rates are on our cryptocurrency prices page.

CoinJar, Inc. is registered with FinCEN as a money services business, NMLS ID 2492913, and holds money transmitter licenses in a growing number of states. You can check whether CoinJar operates in your state before signing up.

How is DOT taxed in the US?

The IRS generally treats DOT as property. A taxable event can occur when you sell it for US dollars, exchange it for another cryptoasset, spend it or give it away.

The IRS explains these rules on its digital assets page. Our guide to downloading a transaction history report for tax shows how to get the records you need. This is general information, not tax advice. Consider speaking to a qualified tax professional about your circumstances.