Compare BTC-to-ETH quotes by the ETH delivered

To compare BTC-to-ETH swap quotes, hold the BTC input and destination constant, then compare the net ETH each route estimates you will receive. A headline exchange rate can hide liquidity fees, destination-chain fees or a different form of ETH. The useful number is the output after deductions, alongside the assumptions that could change it before settlement.

For a native THORChain swap, BTC enters the BTC:RUNE pool, the protocol routes the resulting RUNE through the RUNE:ETH pool, and ETH is sent from a vault to the destination address. The user does not handle RUNE, but the two pool trades both affect the amount delivered. A fuller account of the route and its steps is in thor swap. When comparing it with another quote, check that the other route delivers the same ETH asset on the same chain.

What does the quoted ETH amount include?

The quoted ETH amount should represent the expected output after the protocol’s swap and outbound deductions; the quote’s fee breakdown shows how that figure was calculated. THORChain’s continuous liquidity pools price trades from pool balances. For a single pool, the output follows the pool’s swap formula, and a BTC-to-ETH route applies that mechanism across both pools. The larger the input relative to available liquidity, the more it shifts the pool ratio and the greater the price impact.

Separate fees can make two apparently similar quotes mean different things:

• BTC network fee: paid when sending the input transaction on Bitcoin. It is usually a wallet transaction cost, so confirm whether the displayed BTC amount is before or after it.
• Liquidity fee: charged through the pool swap and reflected in the output. Its size depends on trade size and pool depth.
• ETH outbound fee: deducted to pay for sending the resulting ETH on Ethereum. Check whether the quoted output is net of this fee.
• Affiliate fee: an optional integrator charge. It can reduce output and may differ between interfaces offering the same underlying route.

Compare the same amount of BTC actually entering each route, rather than comparing one route’s wallet balance change with another route’s gross input. If the input is large, check whether the quote uses a streaming swap: THORChain can split execution into sequential sub-swaps, which can reduce price impact but take longer. Its quoted output and timing assumptions are still estimates, not a guarantee that later sub-swaps will execute at the same pool prices.

Why can two quotes for the same swap differ?

Quotes differ because routes use different liquidity, fees and execution assumptions, and because their inputs may have been sampled at different times. On THORChain, pool balances can change as swaps execute. Arbitrageurs may also trade against pools as their prices diverge from external markets. A quote therefore describes expected output under observed conditions; it does not lock the BTC-to-ETH exchange rate by itself.

Check the quote’s expiry and any minimum-output or price-limit parameter. A minimum output sets a floor for acceptable execution; if the swap cannot meet it, a route may refund some or all of the input, with a source-chain outbound fee potentially deducted. Expired quotes should be refreshed, and funds should not be sent using stale deposit instructions. The quote endpoint’s displayed fees and delay estimates help with comparison, but actual confirmation time also depends on the Bitcoin and Ethereum networks.

There is also a denomination trap: “ETH” may mean native ETH on Ethereum or a token representing ETH on another network. Those are not interchangeable for a recipient who needs spendable Ethereum ETH. Verify the destination chain and address format before comparing amounts, then compare net output in the exact asset the recipient expects.

How should you compare quotes before sending BTC?

Use a fixed comparison: same BTC input, same destination chain and address, and same tolerance for execution time and output. Read the fee breakdown rather than subtracting only a prominently displayed network charge. For each route, record net ETH, fees paid separately from the input, quote expiry, and whether execution is immediate or streamed.

For small swaps, a fixed outbound fee can take a larger share of the output, so the highest displayed exchange rate may still deliver less ETH. For larger swaps, pool depth and price impact matter more; a slower streamed route may improve the estimate, but the trade-off is time and exposure to changing pool prices. A quote that cannot meet its minimum output is not a better quote just because its initial estimate is higher.

The practical choice is the route with the best net ETH under assumptions you can accept, after confirming the asset and destination. Refresh the quote immediately before initiating the swap, use the current deposit instructions, and compare the expected ETH with the amount you actually need to receive. That turns a rate comparison into an execution comparison.