- Bot-driven activity on Ethereum contributed to the surge in stablecoin volume and pushed stablecoin swaps on DEXs to a new all-time high.
- Record-low gas fees in 2025 made Ethereum mainnet more attractive for stablecoin activity than competing chains.
- Stablecoin transfers and market cap shifted back from L2s to Ethereum L1, reversing last year’s trend and boosting mainnet dominance.
In May 2025, bot activity on Ethereum registered its largest share ever in stablecoin transfers, representing 57% of volume and 31% of transaction count. Bots on Ethereum made over 4.84 million stablecoin transfers, totaling more than $480 billion last month, also reaching all-time high levels.
Increased bot activity helped lift Ethereum L1 back to the center of DeFi activity, boosted existing operations, and caused significant changes in Ethereum’s DEX volume distribution. Here is why this happened — and what this trend could mean for Ethereum going forward.
Low-Fee Environment Fueled the Bot Surge
The most impactful factor that boosted bot activity on Ethereum has been an over 92% drop in mainnet fees in early 2025. With gas prices hovering below 1 gwei in March and April, Ethereum L1 became more cost-competitive in stablecoin transfers not only compared to other L1 networks but even to its L2s. Most of Ethereum’s gains in overall stablecoin activity this year occurred during this record-low-fee period.
However, stablecoin transfers are the most fee-sensitive type of transactions. For example, following the Pectra upgrade in early May, Ethereum L1 saw elevated fees, which led to a 8% decrease in total stablecoin transaction volume and a $1 billion drop in stablecoin market cap. This slowed the growth of bot activity within the network but didn’t reverse it, as the sector was still riding the momentum from the low-fee period.
Chart: Transaction Fee Comparison Between Ethereum and Its L2s
Record-High Bot Activity Helps Reshape Ethereum’s DEX Landscape
Bots were primarily used for automating swaps, arbitrage strategies, and liquidity routing, which contributed to the spike in stablecoin swap dominance on Ethereum’s DEXs. In April and May, stablecoin swaps held the top spot in Ethereum’s DEX activity for two consecutive months for the first time ever, making up 37% and 32% of total DEX volume, respectively.
As a result, USDT and USDC took center stage, increasing its share in DEX volume (green circle). In March and April, USDC even became the most traded asset on Ethereum DEXs.
Ethereum’s transition to a more stablecoin-focused DEX volume signals a broader transition in Ethereum’s on-chain economy — one that favors utility and payment-focused use cases over speculative trading. In 2025, only two categories saw meaningful DEX volume increases on Ethereum: tokenized assets, which surged by 284%, and stablecoin swaps, up 31%.
Ethereum Eats Up L2s in the Stablecoin Field
One of the major consequences of Ethereum’s bot expansion and reduced fees was that L1 has been increasingly taking the market share from its L2s.
Stablecoin market cap
So far in 2025, Ethereum mainnet’s stablecoin market cap grew by 11%, while the combined stablecoin market cap on L2s shrunk by 1%. For comparison, in 2024, Ethereum mainnet posted a 65% increase, but L2s collectively surged by 218%. The biggest declines in stablecoin supply among L2s this year have come from Optimism, which lost over $700 million.
Transaction Volume
In total, the Ethereum ecosystem, including mainnet and L2s, processed over $11 trillion in stablecoin transaction volume in 2025 to date, triple the volume seen over the same period in 2024. This brought Ethereum’s share of global stablecoin volume to 60%, up from 40% in 2024, indicating that stablecoin activity has been shifting to Ethereum from other L1 networks as well.
At the time of this writing, L1 and L2s were showing a nearly 50/50 split in monthly transaction volume within the Ethereum ecosystem, with mainnet largely reclaiming positions starting March 2025, or during record-low-fee environment.
Transaction Count
In 2022-2024, L1’s share of stablecoin transactions in the Ethereum ecosystem was primarily declining to as low as 22%, since users increasingly favored L2s for their lower costs. But, in 2025, that trend has also flipped. According to GrowThePie data, Ethereum mainnet recorded over 30 million stablecoin transactions this year, lifting its share in transaction count to 42%.
Chart: Transaction Count Distribution Across Ethereum and Its L2s
Final Thoughts
While bots are often associated with sandwich attacks and frontrunning, Ethereum’s increase of bot activity within the stablecoin field shows that they could be among the major drivers to improve market efficiency, boost stablecoin adoption, and enhance DEX performance — a net positive for users and protocols alike.
Still, stablecoin transfers are highly fee-sensitive, meaning that the network may face a trend reverse and user migration outside Ethereum if fees remain elevated. However, if L1 manages to maintain a low-fee environment over time, this could help Ethereum reclaim further market share in the stablecoin space.