Layer 2 coins are the native tokens of blockchains that scale a base chain such as Ethereum or Bitcoin. The L2 chain processes transactions off the main chain and posts a compact summary back to it. Polygon (POL), Arbitrum (ARB), Optimism (OP), and Mantle (MNT) rank among the largest L2 coins by market capitalization.

A Layer 2 chain runs its own transaction execution layer. It posts data and proofs to a Layer 1 such as Ethereum, which finalizes the state. Optimistic rollups assume transactions are valid and allow fraud proofs during a challenge window. ZK rollups submit a cryptographic validity proof for every batch. Both designs cut fees and raise throughput while inheriting most of the L1's security.

Mantle (MNT) is the largest Layer 2 coin by market capitalization on the Kraken category list. It powers the Mantle Network, an Ethereum Layer 2 with its own gas token, validator design, and treasury. Eligible users can buy Mantle (MNT) on CEX.IO with a card, SEPA transfer, or another supported payment method.

Optimistic rollups, such as Arbitrum and Optimism, assume each batch is valid and allow a challenge window during which anyone can submit a fraud proof. Withdrawals to Ethereum usually take about a week. ZK rollups, such as Starknet and ZKsync, attach a cryptographic validity proof to every batch. Ethereum verifies the proof in seconds, and withdrawals can finalize much faster than on optimistic rollups.

Arbitrum and Optimism are both optimistic rollups on Ethereum with their own token, governance, and ecosystem. Arbitrum holds the largest DeFi TVL among Ethereum L2s and runs broad EVM-compatible execution. Optimism powers the OP Stack and the Superchain network of rollups, including Base. Polygon runs a multi-chain stack that started as a sidechain (Polygon PoS) and now includes the Polygon zkEVM rollup; POL is the unified gas and staking token across the stack.

Eligible users can buy Layer 2 coins on both centralized and decentralized exchanges. Centralized exchanges, such as CEX.IO, support fiat payments and offer trading pairs in major currencies. Decentralized exchanges allow direct on-chain swaps but require an external wallet and self-custody.

Instant Buy is the fastest way to buy Layer 2 coins on CEX.IO. Eligible users can buy Polygon (POL), Arbitrum (ARB), Optimism (OP), Mantle (MNT), Starknet (STRK), ZKsync (ZK), and other supported L2 tokens with a credit/debit card, SEPA, Apple Pay, Google Pay, Skrill, or another method available in their region. Each verified user receives a free crypto wallet.

Users can hold Layer 2 coins in custodial or non-custodial wallets. Non-custodial wallets keep the private keys on the user's own device. CEX.IO provides a free custodial wallet to every verified user. The wallet supports POL, ARB, OP, MNT, STRK, ZK, and other listed L2 tokens within one interface.