The core thesis of the Spice Trade protocol is that, there's a massive need for a decentralized, on-chain, open-source, value-stable, scalable, modular, cross-chain, and capital-efficient system for trade among people of the world. Furthermore, such a system should have deep, long-term, and protocol-owned liquidity to reduce friction and maintain tight pegs. It is our belief that creating such a system brings us one step closer to creating a more peaceful and prosperous future for mankind. The first step in building such a system is to re-think 'money' based on the following principles:
On-chain and decentralized: Reduce custodial risk. This stands in direct contrast to centralized stable coins that may have significant custodial risk.
Value-stable: Frictionless trade requires using money whose value does not significantly fluctuate. Value stable is a relative term. For example, depending on the use case, the best money should be designed to be stable relative to national currencies (Such as USD or Euro), a basket of currencies, an inflation adjusted currency, in-game virtual currencies, reward points (imagine a stable coin that traces a hotel or airline point system on chain) etc. The Spice Trade platform allows building appropriate on-chain decentralized money for all these use cases.  
Scalable: Money is a tool of trade. The last thing a successful trade network needs is friction in scaling its monetary system. 
Modular: As we will demonstrate in the rest of this whitepaper, the Spice Trade protocol is fully modular to accommodate both immediately predicted needs as well future unknown use cases.
Open-Source: Creating an open-source ecosystem where anyone with a good idea can contribute and build on top of the Spice Trade protocol is one of our core values
Capital-Efficient: While over-collateralized on-chain stable coins pioneered the non-custodial money movement, we believe they will play a relatively smaller role in the future of money. Let us present the following hypothetical scenario in the real-world economy to demonstrate the point: Imagine we remove all the currencies in the world. Then, in order to generate any new fiat dollar (so that trade can resume), someone has to take a mortgage against their physical assets, and only then money is generated to enter the circulation. This would create such a tight monetary system that any real world economy would come to a screeching halt and collapse. And recent market trends reflects the above reasoning as well. Over-collateralized on-chain stable coins are falling further behind in market cap rankings relative to both centralized and on-chain algo-stable stable coins due to capital inefficiency.
Cross-Chain: History has shown that technology continuously evolves and improves upon itself. And any product, community, or nation that does not evolve with it will ultimately get left behind. As such, we strongly believe that any successful decentralized product that wants to withstand the test of time needs to be a meta concept that stays above any particular blockchain (or blockchain technology) and can easily be extended and expanded from one chain to another. For example, while Proof-of-Stake seems to be the current king of consensus-building algorithms, who knows what the future might bring. Why build a chain based on today's technology and trap your protocol in it, when we know that the blockchain of the future may look significantly different than that of today?  
Protocol-Owned Liquidity based on Starfish Topology: As discussed in future sections, the Spice Trade protocol is designed to have significant liquidity with practically zero cost by building on the concept of Starfish Topology (pioneered by RadioShack: https://docs.radioshack.org/radioshack-defi/terms/disclaimer)

Spice Trade is the first protocol to encapsulate all of the above principles into a suite of value-stable products. 

SpiceUSD

Trust Wallet

MetaMask

Binance Chain Wallet

BRCP TOKEN

sUSD is a synthetic USD token enabled by the Synthetix protocol. It tracks the price of the US Dollar through price feeds supplied by Chainlink’s decentralized network of oracles. sUSD is integrated across the DeFi ecosystem as one of the most liquid decentralized stablecoins, including at Curve. It can be traded without slippage for other assets native to the Synthetix protocol at Kwenta or Synthetix.Exchange.

sUSD

EOSDT

Celo Dollar

Yobit Token

MobilinkToken

Quotient

TranslateMe Network Token

Tratok

Krosscoin

Fei protocol is a DeFi native algorithmic stablecoin. The aim of Fei is to propose a technological solution in a sweet spot between rigid overcollateralized decentralized stablecoin and centralised custodial stablecoins.

Fei Protocol runs on two crypto assets: FEI stablecoin and TRIBE governance token.

FEI is aimed to be a more capital efficient and fully decentralized stablecoin. The protocol uses the value it controls to maintain liquid secondary markets and earn yield for the protocol.

The project was founded in December 2020 and immediately attracted significant interest in the crypto community. It resulted in $19 million VC investment in early March 2021. Among the names that have entered this project are Andreessen Horowitz (a16z), Coinbase Ventures, Nascent and Framework Ventures.

There were some issues with the peg in the original mechanism, but through a series of governance upgrades the protocol recovered in the months following launch.

Fei v2 intends to be a major upgrade for the system and will launch in late 2021. It features 1:1 redeemability for FEI against protocol reserves, TRIBE buybacks and backstop, and algorithmic protocol controlled value management.

Fei USD

BlockCDN

Wrapped Bitcoin Cash

Jinbi Token

Future1coin

OTCBTC Token

USDD is a stablecoin issued by the TRON DAO Reserve. It’s pegged to the value of the US dollar and aims to provide a reliable, decentralized cryptocurrency for blockchain transactions. USDD can be used for payments, trading, staking and as a value store.

USDD is backed by a number of cryptocurrencies, including Bitcoin, Ethereum and TRON. To ensure stability and security, the reserve is over-collateralized, meaning that it holds more assets than the amount of USDD currently in circulation.

USDD

The Gemini Trust Company (Gemini) is a digital currency exchange and custodian that allows you to buy, sell and store digital assets, founded in February of 2014. The GUSD is created by the cryptocurrency exchange Gemini.

The company received approval from the New York Department of Financial Services or NYDFS to launch the stablecoin in September of 2018. The Gemini Trust Company holds USD deposits that correspond to the number of tokens that are in circulation.

When it comes to the Gemini Dollar itself, it is an ERC-20 token that is built on the Ethereum network and has smart contracts that are audited by the security company Trail of Bits Inc.

This dollar is intended to bridge the divide between traditional finance and the crypto industry, due to the fact that this specific stablecoin is completely regulated by the NYDFS.