Users create bitAssets borrowing them. Bitshares is the platform to do that possible. bitGold is a dead market, you can not create more of them at the moment because it "black swanded". bitGold doesn't follow its peg. bitUSD works quite well, it doesn't follow the peg perfectly but is the easiest way I know to short 1x BTS without relying in shady centralized entities. When the market is overinflated is a good refuge. Borrowing bitUSD is useful if you know what you are doing. Leverage is always risky.