Stamp doesn't leverage though.
I don't use them, but are you sure about that?
SEN Leverage allows institutional customers to trade with leverage collateralized by bitcoin. It is powered by the Silvergate Exchange Network (“SEN”), which is used to fund loans and process repayments in real-time, 24 hours per day, 7 days per week. Bitstamp’s role, as Silvergate Bank’s first exchange partner, will be to custody and manage the bitcoin used as collateral.
Bitstamp already uses the SEN network to provide 24/7/365 account funding to eligible customers. We are excited to be working with Silvergate Bank to offer a product that will enable our clients to manage their bitcoin positions with more flexibility.