Sei Network is in the final stretch of a multi-phase protocol overhaul that will transform the chain into an Ethereum Virtual Machine (EVM)-only network, stripping out all Cosmos-based transaction handling and smart contract support. The shift, approved by community governance as SIP-3 in May 2025, is designed to simplify the codebase and lay the groundwork for Sei Giga, the team's next-generation architecture targeting over 200,000 transactions per second. The most urgent consequence for users today is a hard deadline: anyone holding USDC.n on Sei must migrate to native USDC before the end of March 2026.

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What SIP-3 Actually Does

Sei launched in August 2023 as a Cosmos SDK chain with a built-in orderbook module. In July 2024, the team introduced a dual-VM model, running both the Ethereum Virtual Machine and Cosmos' CosmWasm environment side by side. SIP-3 reverses that approach. The upgrade removes CosmWasm smart contract support, eliminates native Cosmos transaction handling, and shuts down the Inter-Blockchain Communication (IBC) bridge that connects Sei to other Cosmos chains.

The Sei team's stated rationale draws on a performance analogy published on the official Sei blog: "To make a car go fast, you can either increase power or reduce weight." The upgrade removes hundreds of thousands of lines of code from the protocol, choosing weight reduction over added engine power. Full transition to EVM-only is expected by mid-2026, with the IBC inbound transfer "kill switch" already activated on testnet as of March 2026.

SIP-3 was not imposed unilaterally by Sei Labs. The proposal went through community debate with on-chain validator participation, and multiple phased governance proposals accompany each software release in the series.

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The USDC.n Problem

USDC.n is USDC that arrived on Sei via the Noble IBC bridge, making it a Cosmos-native asset incompatible with the post-SIP-3 EVM-only environment. Approximately $1.4 million worth of USDC.n currently sits on Sei. Once IBC is fully disabled on mainnet, that balance becomes inaccessible unless migrated beforehand.

Users have three options. The simplest is swapping USDC.n for native USDC directly on a Sei decentralized exchange such as DragonSwap or Symphony. The second option is using brrr.fun, an automated tool that routes funds through Noble, Polygon, and back to Sei using Circle's Cross-Chain Transfer Protocol. The third is a manual bridge through an intermediary chain such as Base, which Sei Network itself recommends only for users who are technically comfortable with multi-chain bridging.

One complication affects DeFi participants specifically. Users with USDC.n deposited in lending protocols, including roughly $194,000 in Yei Finance and approximately $13,000 in Takara Lend, must withdraw those positions before attempting any migration. Moving the funds while they remain locked in a lending position is not possible.

According to Cryptopolitan's reporting on the network upgrade, Cosmos-native assets like USDC.n will not be supported after the transition.

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What Sei Giga Is Building Toward

SIP-3 is not an end goal. It clears the foundation for Sei Giga, which introduces Autobahn, a custom Byzantine Fault Tolerant consensus protocol that allows multiple validators to propose blocks at the same time. The team describes it as the first multi-proposer EVM Layer 1. The execution client is built from scratch rather than forked from existing Ethereum clients, enabling parallel transaction processing, ahead-of-time compilation, and asynchronous state root generation.

Sei Labs co-founder Jay Jog has said: "Sei Giga is not just another EVM chain; it's a reimagining of what's possible for blockchain performance."

The targets are ambitious: sub-400ms finality and throughput of 5 gigagas per second. The team also projects three discrete performance improvements over the current EVM standard. Execution efficiency is projected to improve 40 times over current levels; throughput is projected at 50 times current EVM capacity; and block production speed is projected to be 70 times faster than the current EVM standard.

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Regional Stakes: South Asia and Africa

For developers and users across South Asia and Africa, the direction of SIP-3 is broadly favorable, with one immediate caveat.

The EVM is already the dominant development stack in markets like Nigeria, Kenya, India, and Pakistan. Solidity expertise is common; CosmWasm's Rust-based tooling is not. The removal of CosmWasm lowers the barrier for regional builders who previously had little reason to engage with Sei's Cosmos layer. The Giga performance targets, particularly sub-400ms finality and high throughput, are directly relevant to mobile payment and remittance use cases that are growing across both regions.

The simplified EVM-only architecture that SIP-3 creates also underpins a concrete distribution initiative: in December 2025, Sei announced a pre-install agreement with Xiaomi, a move particularly relevant to mobile-first markets in South Asia and Africa where smartphone penetration outpaces desktop crypto usage.

The immediate concern is the USDC.n deadline. While $1.4 million is a modest sum in aggregate, individual exposures matter in markets where a few thousand dollars represents significant savings. Regional crypto community moderators and local media should treat the March 2026 deadline as an active alert.

Sei has announced a $50 million Japan Ecosystem Fund targeting gaming and entertainment startups, but no equivalent program has been announced for South Asia or Africa, a gap relative to the network's broader regional aspirations.

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What Comes Next

Additional mainnet releases, planned but not yet dated, will disable outbound IBC transfers and replace Sei's native oracle with Chainlink, Pyth, and API3. CosmWasm developers who built on Sei face a complete rewrite of their applications in Solidity or Vyper; those unwilling or unable to do so will need to migrate to another Cosmos chain.

SEI currently trades at approximately $0.07, roughly 94 percent below its all-time high of $1.14, with a market cap near $473 million. Of the total 10 billion token supply, approximately 6.7 billion are currently in circulation, with full unlock scheduled for August 2027. DeFi total value locked on the network stood at around $560 million in January 2026, down from a peak of $687 million in August 2025. The chain's next performance test will come when Giga moves from whitepaper to mainnet.