When dealing with trading pairs in the crypto and fiat world, consistency and clarity are essential. A mismatched or inverted trading pair can confuse users, disrupt data flows, and complicate downstream integrations. To ensure that our pair mapping remains logical, standardised, and easy to interpret, we’ve established a clear dominance hierarchy for quote currencies.

Here’s the hierarchy we use for determining quote currency dominance:

USD > FIAT > Stablecoin > BTC/Wrapped BTC > ETH/Wrapped ETH > Other Crypto

For crypto-to-crypto pairs, the first mapping always takes dominance. For example, if XRP-EOS is mapped first, it will always stay as XRP-EOS, and never invert to EOS-XRP. This prevents unnecessary remapping and maintains consistency across markets.

Why This Hierarchy?

1. USD as the Global Standard
   The US dollar (USD) is the world's reserve currency and the primary fiat for trading pairs across almost all markets. By enforcing USD as the dominant quote, we align with global trading norms. This ensures that pairs like EUR-USD and GBP-USD are presented in the universally recognised format, reducing confusion and making price comparisons easier.
2. Fiat Dominance Over Stablecoins and Crypto
   Fiat currencies (EUR, GBP, etc.) represent direct government-backed money, inherently carrying more stability than stablecoins or crypto. While stablecoins like USDT are pegged to fiat, their dependence on third-party issuers introduces potential risks. By prioritising fiat over stablecoins, we emphasise the reliability and direct liquidity that fiat brings to trading pairs.
3. Stablecoins as the Next Logical Tier
   Stablecoins provide a crucial bridge between fiat and crypto, offering the benefits of blockchain without the volatility of native crypto assets. However, their value still fundamentally derives from fiat currencies. This makes stablecoins dominant over crypto assets like BTC and ETH, but secondary to fiat. For example, USDT-BTC should always invert to BTC-USDT, ensuring stability is reflected in the quote position.
4. BTC/Wrapped BTC Over ETH/Wrapped ETH
   Bitcoin (BTC) is the original and most dominant cryptocurrency by market cap. Its role as "digital gold" gives it priority over Ethereum (ETH) and other assets. Even wrapped versions of BTC (WBTC) retain the dominance of the native BTC. Therefore, pairs like WBTC-ETH invert to ETH-WBTC to reflect BTC's position at the top of the crypto hierarchy.
5. ETH/Wrapped ETH Over Other Cryptos
   Ethereum, as the leading platform for decentralised applications and smart contracts, ranks just below BTC in dominance. Wrapped versions of ETH (WETH) follow the same logic as WBTC. This hierarchy ensures that assets like ETH-XRP stay as ETH-XRP and not the other way around.
6. Other Cryptocurrencies
   For all other cryptocurrencies (XRP, LTC, EOS, etc.), dominance is determined by the first pair mapping. If XRP-EOS is created first, future references to this pair will always default to XRP-EOS to avoid unnecessary inversions or inconsistencies.

Handling Exceptions:

First Mapping Wins (Crypto-to-Crypto Pairs)
Crypto-to-crypto pairs can sometimes lead to ambiguities. To address this, we enforce the “first mapping wins” rule. If XRP-EOS is initially mapped, it will stay in that order for future transactions, regardless of which asset might seem dominant otherwise. This prevents volatility-driven inversions and ensures continuity.

Manual Overrides and Custom Mappings
While our dominance logic covers most cases, we recognise the need for manual overrides. Users can manually map pairs in any order (USD-RandomAsset), and the system will respect that mapping moving forward. The only way to alter this is by deleting the existing mapping.

Why This Approach Matters

• Consistency Across Markets: By enforcing a clear hierarchy, we ensure our trading pairs align with industry standards, reducing the chance of mismatched data.
• Simplified User Experience: Traders expect to see pairs like BTC-USDT or ETH-USD. Inverting these unnecessarily adds friction and confusion.
• Predictability and Reliability: The “first mapping wins” rule prevents arbitrary remapping, ensuring trading pairs remain stable even as markets evolve.

Our goal is to create a structured, intuitive trading environment that mirrors the natural dominance of currencies and assets. This approach not only simplifies the trading process but also helps maintain trust and clarity for all users interacting with our platform.

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