Tokenized Cash Just Became Wall Street's Favorite Collateral as BUIDL Broke Above $2.5 Billion

Cash that lives on-chain just turned into prime collateral, and desks moved fast. BlackRock's BUIDL token pushed past $2.5 billion in size after $610 million of fresh mints in five sessions. The fund holds T-bills, cash, and repo, with daily value updates and same-day cash-out for approved wallets. A top trust bank holds the assets, while transfer agent ops run 24 hours a day. For a trading firm, that mix of yield plus instant move is rare.

The math forced the shift. BUIDL accrues about 5.2% a year and settles like a stablecoin. Firms can pledge it at prime brokers, borrow USDC near 4.9%, and run basis or market-neutral books. The 30 to 40 bps spread looks small, but on $500 million it pays for a full team. More vital, redemptions clear in minutes, not T+1, so treasuries avoid idle cash at banks. In July, two large brokers opened BUIDL margin lines, and $320 million shifted out of idle stablecoins into the token in 72 hours.

How it is used now shows why size keeps rising. A large market maker runs perps hedged with spot and posts BUIDL as cover, cutting funding cost by 55 bps. A credit fund built a loop: mint BUIDL, wrap via Ondo into OUSG, post on Flux, borrow USDC at 5.0%, buy more BUIDL. That loop alone added $90 million of demand. On Curve, a BUIDL/USDC pool holds $110 million and keeps 1 bps spreads, since arbitrage to off-chain redemption is instant. Even DAO treasuries joined. Three large DAOs moved $48 million of stable reserves into BUIDL for payroll in Q3.

Flow data backs the bid. Net stablecoin mint on Ethereum was $1.1 billion on the week, but supply on exchanges fell $340 million, a sign cash went to yield tokens. Aave and Compound USDC borrow rates fell 60 bps as high-grade collateral crowded out weaker assets. Perp funding eased as market makers funded stock with BUIDL loans rather than costly USDT credit. ETH staking at 3.1% looks thin next to 5.2% cash with daily liquidity, so ETH/BTC ratio softened 2.3%.

The trade is clear for pros. Hold cash where it earns and moves. BUIDL acts as a dollar that yields, clears in a block, and is accepted as margin. The loop lifts stablecoin liquidity, lowers perp cost, and tightens borrow rates across DeFi. It also sets a floor for rates on-chain. When risk-free cash pays 5% in a wallet, every other curve must reprice.

What to watch is redemption. BUIDL allows daily cuts, yet a custodian pause or a bank holiday could gap the secondary price. Smart contracts that list it need breakers and NAV oracles with proof. Access is still permissioned, so a loss of a key broker license could split liquidity. For now, demand is deep, supply is clean, and cash has found a home on-chain that desks trust.

#RWA #BUIDL #Tokenization #Treasuries #DeFi