Solana's stablecoin supply reached $17.39 billion, a new high, after rising $1.26 billion, or 7.8%, in 24 hours from about $16.13 billion on September 24. SolanaFloor attributed the expansion to approximately $751 million in USDC minted by Circle and about $530 million in USDT minted by Tether, while a separate onchain record documented an exact 250 million USDC mint through Circle's authorized infrastructure. The record came three days after the previous high of roughly $16.87 billion on September 22. USDC remained Solana's largest stablecoin at $8.23 billion, or 47.31% of supply, ahead of USDT at $2.66 billion; USDC's share had fallen to about 44% last week from 80.3% at its February 2025 high. Separately, the Federal Reserve proposed two rules on September 24 to implement the GENIUS Act for payment stablecoin issuers under its supervision, opening a 60-day public-comment period.