Trade

The Fulcrum portal (https://fulcrum.trade) is a front-end web interface for interacting with the bZx smart contracts. Fulcrum is built on the bZx base protocol and extends the protocol by allowing both loans and margin positions to be tokenized. Tokenized loans, called iTokens, are for letting the user lend their assets and earn interest. Tokenized positions, called pTokens, are for gaining long or short market exposure to an asset, and for letting the user trade with borrowed funds and with leverage. Both iTokens and pTokens are ERC20-compliant and provide access to the read-only functions symbol, name, decimals, totalSupply, balanceOf, and allowance, as well as the state-changing functions transfer, transferFrom, approve, increaseApproval, and decreaseApproval. Collectively, we'll refer to both iTokens and pTokens as "Fulcrum tokens".

Lend

Lending on Fulcrum is powered by iTokens, which are global lending pools. Each asset has a single iToken equivalent (ETH as iETH, DAI has iDAI, etc.), and has an independent interest rate paid to lenders who have deposited funds to the contract. The interest earned is proportional to the amount of iToken held by each lender. iTokens are minted by transferring the underlying asset to the contract, calling mint, and receiving back an equivalent amount of the iToken (ERC20) at the current iToken price. iTokens have an on-chain API to query current "redemption value" (tokenPrice()), as well the interest rates paid by borrowers and paid to lenders.

Trading & Borrowing

Trading (taking a position) involves first borrowing from an iToken.

There are two ways to borrow using Fulcrum and open a position:

• pToken contracts are tokenized versions of leveraged long or short positions on an asset. pTokens are minted by sending ETH or another asset into the pToken contract, which in turn borrows from an iToken lending pool, does a Kyber swap, and sends the user back an equivalent amount of pToken (ERC20) at the current pToken price. For short positions, such as 2x short ETH, the pToken borrows from the iETH token, then swaps that ETH for a stable asset (DAI) on KyberSwap. For long positions, such as 2x long ETH, the pToken borrows from a stable asset, iDAI, and swaps that for ETH on KyberSwap. The tokens are perpetual, but positions are not. If a position loses too much value, or reaches the end of the loan term (28 days), it will be liquidated and a new position will be opened behind the scenes. Traders should be aware of the liquidation price of the pToken, and burn their pTokens prior to being liquidated, to avoid locking in any losses.

• A trader can borrow directly from an iToken and manage their loan or margin trade themselves using the bZx protocol. The protocol supports margin loans that are under-collateralized or over-collatateralized. Over-collateralized loans, with 150% collateral or more, allow the user to withdraw the loan principal to an external wallet or contract.