BDollar Protocol

The bDollar Protocol is an algorithmic stablecoin running on the Binance Smart Chain. The main protocol consists of bDollar (BDO), bDollar Shares (sBDO), and bDollar Bonds (bBDO). The intent of the main protocol is to push the price of one BDO to the target price of one U.S. dollar through adjustments to the supply of BDO. On 31 March 2021, the bDollar Protocol introduced Multi-Peg tokens.

## Definitions

**Epoch:** A specific period of time.  In the protocol, either 6, 8, or 10 hours.

**TWAP** (time-weighted average price): The price of BDO (or a multi-peg token) averaged out over a given epoch.

## How Does it Work?

The bDollar Protocol utilizes the concept of an algorithmic central bank that can manage the circulating supply of BDO. That is to say, BDO is an **algorithmic** stablecoin and is not backed by collateralized assets. BDO is NOT a fiat stable.

***Generally speaking***, when the market price of BDO averages over 1 USD for a specific period of time (an epoch), the protocol enters an expansion phase, by which new BDO is minted, putting downward pressure on the price of BDO back to 1 USD. In contrast, when the market price of BDO averages below 1 USD for an epoch, bonds become available to purchase, reducing the circulating supply of BDO and therefore putting upward pressure on the price of BDO back to 1 USD.

### During an Expansion

When the TWAP for BDO exceeds $1.00 for a given epoch, the protocol is in expansion. During expansion, new BDO is minted to help push the price of BDO down, with the majority of the new tokens going to Boardroom stakers. The current distribution of BDO during expansion is as follows:

* 80% of newly minted BDO goes to the Boardroom to those staking sBDO.
* 15% is for the DAO Fund.
* 3% of newly minted BDO is added as a bVaults incentive.
* 2% of newly minted BDO is used for marketing activities.

The actual rate of BDO expansion is dependent on the TWAP price. If the TWAP is 1.001, the rate of expansion is 0.1%. If the TWAP is 1.005, the expansion rate is 0.5%, and if the TWAP is 1.01, the expansion rate is 1%. The expansion rate is further capped by Total BDO Supply as follows:

Expansion Rate Caps
 2M+
 5M+
 10M+
 20M+
 50M+
 100M+
 200M+
 1B+

Additionally, the duration of an epoch during expansion is now dynamic based on the TWAP:

* 6 hours if the TWAP <= 1.0125
* 8 hours if the TWAP is between 1.0125 and 1.025.
* 10 hours if the TWAP > 1.025.

### During a Contraction

When the TWAP is below $1.00 for a given epoch, the protocol is in contraction. During contraction, the protocol allows for the burning of BDO for bBDO at a 1 to 1 ratio, taking BDO out of its circulating supply. Only a limited amount of bBDO is available during a given epoch, which is always 6 hours in duration during a contraction.

Redemption of bBDO for BDO when the TWAP remains below $1.00 will result in a 10% loss. That is to say, 1 bBDO redemption will result in 0.9 BDO.

### Following a Contraction

When the protocol enters an expansion following a contraction in which bonds were purchased, it enters the "Debt Phase". During the Debt Phase, expansion is increased by 50% of the predetermined expansion rate. 50% of the minted BDO is allocated to the Protocol's Treasury Funds to prepare for the redemption of bonds. Once the amount of BDO in the Treasury Fund is at a level to meet all circulating bond redemption, the Protocol leaves the Debt Phase and returns to normal expansion.

## Multi-Pegs

In March 2021, the bEarn.fi team introduced the concept of "multi-pegs" to the bDollar protocol. At its core, multi-pegs operate like BDO in that they remain algorithmic tokens. Instead of being pegged to the US dollar, though, each multi-peg token is pegged to its corresponding currency, token, or commodity.

If the multi-peg token trades below its current market price, token holders can purchase coupons at a discount. The coupons operate like bBDO, reducing the circulating supply of a given multi-peg token.

If the multi-peg token trades above the current market price, the contract allows for the redemption of coupons to burn the supply. When the price stays above market price, the contract will mint more of that multi-peg token, with rewards distributed to sBDO boardroom stakers.

The bEarn.fi team plans on introducing more than 20 multi-peg tokens. When any (or all) of these are in expansion, the rewards will be going to sBDO boardroom stakers, with the potential for rewards from all of these tokens at once.

## History

* 25 December 2020: bDollar was introduced. https://bearn-defi.medium.com/introducing-bdollar-f6152aeae737
* 31 March 2021: Multi-Pegs introduced with bpDOT.