As part of mainnet pre-alpha portfolio margin, USDH has been added as borrowable, and UBTC has been added as collateral.

To recap, the initial limits for pre-alpha are:
+ Master account >$5M in weighted volume required before enabling portfolio margin
+ USDH: 5M USDH global supply cap, 1M USDH global borrow cap, 50k USDH user supply cap, 1k USDH user borrow cap
+ USDC: 5M USDC global supply cap, 1M USDC global borrow cap, 5k USDC user supply cap, 1k USDC user borrow cap
+ HYPE: 200k HYPE global supply cap, 200 HYPE user supply cap
+ BTC: 100 BTC global supply cap, 0.1 BTC user supply cap

The pre-alpha phase is for feedback and should ideally be tested on a small sub-account with <$1k in value. Bug reports are eligible for generous mainnet bug bounties. Feedback is also greatly appreciated.