1. Introduction

1.1 Origination

1.1.1 What is Yearn and YFI?

Yearn is a yield aggregator for DeFi lending platforms that rebalances for highest yield during contract interaction which supports Compound, dYdX, Aave and DDEX protocols. When users put their money into the platform, it automatically transfers the assets into the protocol that has the highest yield, and returns a proof of stake called yToken. Users can send back yTokens at any time to withdraw their deposits along with the interest.
Moreover, Yearn and Curve together created y.curve.fi, a pool for stable coin exchange. Besides enjoying the interest on lending, yToken holders can put their tokens into the exchange pool of y.curve.fi to become a market maker, generating extra incomes. Such a combo now ranks first among all DeFi platforms by APR.

(Andre Cronje)
YFI is the token used for governing Yearn protocol. Its initiator Andre Cronje admitted that he had no interest in participating in the governance and wished the community to be autonomously organized. Until July 26th, YFI has been issued to yield farmers who provide liquidity to the pools (Info from debank.com).

1.1.2 YIP-8 and forking of YFI?

As mentioned above, the mining/farming of YFI has stopped on July 26. In order to prevent a sharp drop in liquidity of the pools, the community proposed YIP-8, suggesting a weekly halving model for yield farming. Though more than 80% of the votes are FOR the proposal, it has been declined because of the unmet 33% quorum requirement. To protect Andre’s genius design from being spoilt by whales, we forked YFI, naming it YFII. The issuance of YFII imitates the halving model of Bitcoin so that the tokens will be fairly distributed to the community.

(Yearn Improvement Proposal 8)

(FOR votes of YIP-8 exceed 80.07% but the proposal is still declined due to early farming whales’ intervention)

1.1.3 How and when was YFII launched?

YFII belongs to the community. No pre-mining. No ICO. No dev team rewards. The only way to get YFII is to provide liquidity to the pools. YFII is the token for community governance and the key to farming yields of various DeFi platforms. It is used for revenue allocation and voting in the YFII DAO.

• Time of the YFII Genesis: UTC 16:00 July 27, 2020
• Pool 1 opening: UTC 16:00 July 27, 2020
• Pool 2 opening: UTC 16:00 July 28, 2020

1.2 Token Design

1.2.1 Token design of YFII

The total supply of YFII is 40,000. Each of the two pools will be emitting 20,000 tokens to yield farmers, starting at 10,000 in the first week halving every 7 days. The number of tokens farmed is in proportion to the liquidity farmers provide to the pools. YFII will be completely distributed in the following 10 weeks.

1.2.2 Burning of admin key

People may be worrying that if the developers would issue infinite number of YFII tokens to steal their money. The answer is: impossible. The minting keys have already been burnt by transferring the admin role to the blackhole address (0x00) so that no one has this privilege to mint new tokens. You can examine the burning txns below which are also documented at a specific page.
YFII Token Governance Key
https://etherscan.io/tx/0xd491dd5d190c6856f12cd88a8d318e71c5317371286379053a77040d09d27839
Yearn Reward Distribution Key
https://etherscan.io/tx/0xb78ff92dcdbc4fb2e69bfbd2aa2975d78e57983070c910121dbb77c03a28f53f
https://etherscan.io/tx/0x8d121a5dfd3808cb1ba8e5124dff01807c50a5fa769b77db7993eda6f4da38e8
Balancer Reward Distribution Key
https://etherscan.io/tx/0x26037582e80e9e668d8a8d16f7811441ff4db979ff63d0beb5c931c7fc9e7956
https://etherscan.io/tx/0x595088895e902fdbafb133c7d2b14e0264bfb4d400bb2928d27e1c10f4f05ac5
addMinter record
https://api.blockchair.com/ethereum/transactions?q=input_hex(%5E983b2d56),recipient(0xa1d0E215a23d7030842FC67cE582a6aFa3CCaB83),recipient(0xa1d0E215a23d7030842FC67cE582a6aFa3CCaB83))

1.3 YFII Finance

1.3.1 YFII pools

• Pool 1: YFII and CRV (governance token of curve.fi platform);
• Pool 2: YFII and BAL (governance token of Balancer, available when whitelisted);
• Pool 3: Stake YFII to earn interest on Yearn protocal;
• …
• Pool N: Integrating more business from YFI while innovating YFII’s own.

  1.3.2 YFII Vault

  New vault: https://dfi.money/#/vault

2. User Guide

2.1 Yield Farming

2.1.1 Pool 1: Curve yCRV

If you are farming YFI, exit from YFI Pool 3 and withdraw BPT. Go to Balancer and remove liquidity to get back yCRV and YFI. You’ll need yCRV to farm YFII. Below are the detailed instructions.

1. Visit https://ygov.finance/staking and connect to Metamask. Open Governance (Pool 3).

1. Click Exit: Claim and Unstake to withdraw your staked BPT and rewards.

Note: If you ever voted, your stake will be locked for 3 days before you can unstake.

1. Go to yCRV/YFI pool on Balancer. Choose Max under All Pool Assets and then click Remove Liquidity to get back your yCRV and YFI.

If you have never farmed YFI and this is the first time you farm YFII, go to the Y pool on Curve and deposit any one or any combination of USDT/DAI/USDC/TUSD to get yCRV. Don’t click on other buttons other than Deposit because they may cost you extra gas.

Now you have yCRV in your wallet and are ready to farm YFII. Go to https://yfii.finance and click Stake. Open the yearn pool (Pool 1).

Click Stake and Metamask will ask you to authorize two transactions (one for permission to spend and the other for staking).

2.1.2 Pool 2: DAI-YFII Balancer

1. You need DAI in your wallet before farming. Stake assets in Maker to borrow DAI or go to your favourite exchange to buy DAI.
   

2. Go to the DAI-YFII balancer pool and setup Balancer Proxy first.
   a) If you have YFII, choose All Pool Assets. Unlock DAI and YFII (0xa1d0E215a23d7030842FC67cE582a6aFa3CCaB83) by sending two transactions and then they become unlocked. Input the amount you are going to deposit in either box of DAI or YFII, and the page will input the corresponding amount of the other for you. Click Add Liquidity to send a transaction and then you get BPT.
   
   b) If you don’t have YFII, choose Single Asset. Unlock DAI and input your deposit amount. Then click Add Liquidity. The system will buy the corresponding amount of YFII needed for you and then you get BPT.
   

3. Go to https://yfii.finance and click Stake. Open the balancer pool (Pool 2) and you’ll see your BPT amount. Stake BPT to begin farming YFII.

2.1.3 Pool 3: YFII

TODO: Stake YFII to get yCRV rewards. (the rewards has been stopped)

2.2 Vault

2.2.1 What is YFII Vault?

YFII Vault is a yield aggregator for farming pools that targets highest APR using a set of strategy contracts. Basically you deposit the token it supports and automatically get the yield that the strategy has farmed. Everyone is welcomed to write their own strategies and those with the highest votes from the community will be implemented. The Vault also saves you tons of gas during complex contract interactions because all you need to do is just deposit and withdraw.

2.2.2 How to use the Vault?

New version (DFI frontend)

A new frontend (dfi.money)has been developed by the community along with a set of new strategies. You can deposit any of the assets on the list and the strategy contract automatically farms the yield and swaps it for YFII tokens for you.

New Features

• In the past versions, a whale could make a sudden deposit to dilute others’ incoming and then immediately withdraw its funds. Now this exploitation is no longer possible because the income will be emitted gradually in the following 24 hours after each deposit. For example, if a user claims the yield 8 hours after the last deposit transaction, he/she only gets 1/3 of the yield. Please note that the 24-hour countdown will be reset each time when the user deposits into the Vault.
  
• Anyone can invoke the Harvest function to collect yields into the vault and in return get 1% of the YFII tokens in that batch. It may cost gas of approximately 0.1 ETH. Frequent harvesting can help reduce the slippage during token swaps and thus increase the whole income of the Vault. Please keep an eye on the current yield and also check if others have already invoked the function recently, or the rewards won’t cover your gas fee.
  

1. This guide supposes you choose to deposit WETH into the Vault. First go to the new Vault website and connect your wallet. Click Vault to enter the Vault interface.
   
2. Expand WETH section and input the number you’d like to deposit. If it’s the first time you deposit, click Approve to allow the contract to spend your WETH. After the Approve transaction is confirmed, the button will become Deposit. Click the Deposit button to deposit WETH into the Vault. After the txn is confirmed, your farming automatically starts and the Vault begins to generate yield for you.
   

1. You can see how many WETH you’ve deposited into the Vault in the Deposited section. You can withdraw at any time and when withdrawing, your yield (if there are any available) will be claimed at the same time. The Earned section displays how much you have actually earned in this Vault. You can claim your yield at any time without withdrawing your deposit. Please not that your claimable yield is released evenly in 24 hours after your last deposit. The Pending section indicates the estimated yield to be harvested into the Vault (and to become your Earned balance).

1. An ordinary user can safely ignore the Farm and Harvest buttons. However, if you’d like to contribute to the community, you can spend your own gas to help the Vault send idle balance to the farm by clicking Farm button. You can also click Harvest to help the Vault finalize its pending earnings, and in return you’ll be rewarded with 1% of the yield of that harvest.

Old version

YAM strategy
The first strategy online is the one that farms YAM pools. Users deposit any one of SNX/LEND/MKR/AMPL/YFI/COMP/LINK/WETH tokens into the YFII vault and enjoy yileds of YFII tokens.

1. This guide supposes you choose to deposit WETH into the vault. First you have to swap ETH (or any other tokens you have) for WETH. Go to UNISWAP, choose ETH in the From section and choose WETH in th To section. Input the number you’d like to swap and click wrap. The price is always 1:1.

1. Go to YFII Vault page and expand the WETH section. You can see your balance of WETH on the left. Input the amount you’d like to deposit and then click Deposit. If it’s the first time you deposit WETH you’ll have to send an approve txn (see the popup window of Metamask). When it’s approved, Metamask will popup again for you to send the actual _Deposit_transaction. After the txn has been confirmed you’ll see your WETH balance on the right side which means you have such an amount of WETH in the vault which is farming the best yield according to our strategy.

1. You can claim your yield at any time by clicking the Claim button on the right. If you’d like to exit the Vault, click Withdraw. The transaction will also claim the yiled for you when exiting.

2.2.3 CRV strategy

The CRV strategy farms CRV tokens of Curve DAO by depositing yCRV (Y pool LP token of Curve) and automatically swaps CRV for YFII tokens as the final yield.

1. To farm with this strategy, you need to have yCRV in your wallet first. Go to Curve’s Y pool and deposit any one or any combo of USDT/DAI/USDC/TUSD to get yCRV.

The above transaction may cost about 0.3 ETH worth of gas, so if you’re playing with a small amount of fund you may want to buy yCRV directly on Uniswap. Set the target token to 0xdf5e0e81dff6faf3a7e52ba697820c5e32d806a8 (yCRV) and swap.

1. Now you’ve got yCRV tokens. To join the Vault, go to YFII Vault page. Input the number of yCRV you’d like to deposit on the left side and then click Deposit. After the txn has been confirmed, the Vault starts to farm for you.

2.3 Trading YFII

2.3.1 Uniswap

Go to Uniswap. Choose ETH in From section and choose YFII (or paste in the contract address 0xa1d0E215a23d7030842FC67cE582a6aFa3CCaB83) in To section to trade. Please keep an eye on the price slippage when it’s in the early stage.

2.3.2 Balancer

Go to Balancer. Choose DAI at one side and choose YFII (or paste in the contract address 0xa1d0E215a23d7030842FC67cE582a6aFa3CCaB83) at the other side to trade. Please keep an eye on the price slippage when it’s in the early stage.

2.3.3 Other DEXes

2.3.4 CEXes

Huobi: https://www.huobi.com/en-us/exchange/yfii_usdt/

2.4 Governance

Multi-sig

TODO https://github.com/yfii/keys

Proposal：https://gov.yfii.finance/c/proposals/5

Voting：https://yfii.finance/#/vote

3. For developers

Github: https://github.com/yfii