Altcoins SEI, ARB, OP Surge as Bitcoin Rally Fuels Altseason

After Bitcoin reached a new all-time high, capital began to flow into major altcoins such as SEI, ARB, and OP. This shift is indicative of the start of the next phase of the bull run, often referred to as “altseason.”

The altcoin market, including Sei (SEI), Arbitrum (ARB), and Optimism (OP), experienced a rally in tandem with Bitcoin over the past two days. This capital rotation has been escalating in recent weeks, with notable cash inflows into U.S. spot Ether ETFs amid rising demand for altcoins from institutional investors. More than a dozen spot altcoin ETFs are awaiting final decision from the U.S. SEC. The TOTAL3 market cap, which excludes Ethereum and Bitcoin, has broken out of a falling logarithmic trend established year-to-date, suggesting the onset of the awaited 2025 altseason.

SEI Network has led the charge, surging over 20% as its on-chain metrics show booming growth. The mainstream adoption of DeFi protocols by institutional investors and retail traders, along with notable developments in the Sei network, has fueled the price rebound of SEI. Since the launch of Sei V2 last year, its total value locked (TVL) has grown exponentially from $96 million to around $668 million. The adoption of the Sei network by institutional investors, including the integration of Circle’s Cross-Chain Transfer Protocol v2 (CCTP v2), has helped SEI price regain bullish sentiment. SEI price surged over 20% in the last 24 hours to trade about $0.32. From a technical analysis standpoint, SEI price rebounded from a crucial support level around 25 cents, thus eyeing the next midterm target of around 46 cents. The daily MACD indicator has recorded growing bullish histograms as the Relative Strength Index (RSI) attempts to rally above the 70 level for the first time in 2025.

The Arbitrum (ARB) network has grown to a vital layer-two scaling solution within the Ethereum ecosystem, bolstered by mainstream adoption from institutional investors. The Arbitrum network is the second-largest L2 scaling solution after Base chain, with a total value locked (TVL) of about $2.59 billion and a stablecoins market cap of around $3.26 billion. In the past 24 hours, ARB price surged over 14% to trade about $0.423. As a result, the mid-cap altcoin, with a fully diluted valuation of about $4.1 billion, has broken out of a falling megaphone structure in the daily timeframe. From a technical analysis standpoint, ARB price is well-primed to reach 47 cents soon after rebounding from a double-bottom, which was coupled with a rising divergence of the daily RSI.

The Optimism (OP) network is a major L2 scaling solution within the Ethereum ecosystem. As of this writing, the Optimism network has a total value locked of about $412 million and a stablecoins market cap of around $679 million. As a result of the rising adoption of the Ethereum DeFi ecosystem in the recent past, OP price has surged over 25% in the last two weeks. The mid-cap altcoin, with a fully diluted valuation of about $2.8 billion, is now well-positioned to kickstart its macro bullish trend.