If you need to exchange Ethereum tokens from your own wallet, Fermi swap is a decentralized venue that fills trades from its own token inventory. You choose what to sell and receive, review a quote, and authorize an on-chain transaction. The amount you ultimately receive depends on the quote available when the trade executes and the minimum output you accept.
Key points
- Fermi trades against a market maker’s inventory rather than a shared liquidity pool.
- Compare the amount received after gas, especially for a small trade.
- A quote is usable only if inventory and your minimum output still permit execution.
The Trade Uses the Maker’s Inventory
Fermi supplies the other side of the exchange from inventory held for trading on Ethereum. This is a proprietary automated market maker, or pAMM: a market maker updates its prices instead of leaving a passive pool curve to determine every price. In a Uniswap V3 pool, by comparison, the price moves through deposited liquidity as trades consume it; here, the maker’s current quote and available inventory determine what it can fill.
fermiswap.pro is the Fermi service for exchanging tokens directly from your wallet. A Fermi swap does not require a preliminary deposit into an exchange account: your wallet authorizes the trade, and the input and output transfers settle on chain. You retain control of the input tokens until a transaction executes, although an ERC-20 approval can authorize a contract to spend them.
The tokens must be the assets you intend to trade on Ethereum. WETH is an ERC-20 form of ETH, while cbBTC represents bitcoin as a token; receiving cbBTC does not put native BTC in a Bitcoin wallet. If your starting asset is on another network, an Ethereum token swap alone cannot move it across chains.
The Quote Can Change Before the Trade Settles
An Ethereum Fermi swap quote is a price for a specified input amount at a particular moment, not a reservation of inventory. The market maker can revise its buy and sell prices as the market moves. In Titan Builder’s pAMM flow, updated maker prices can be ordered ahead of taking trades within a block, so execution uses more recent pricing than an earlier quote might suggest.
From end to end, the wallet authorizes spending, the trade is submitted, and the executing contract checks the available terms. If the trade remains valid, it takes the input token and sends the output token in the same on-chain transaction. A minimum output protects you from receiving less than you agreed to; if execution cannot meet it, the transaction can revert, though network gas may still be spent.
Inventory matters as much as the displayed price. A maker may be able to quote $1,000 of WETH for USDC but offer a different effective rate, or no usable quote, for $100,000 because the larger order draws more heavily on one side of its inventory. Raising slippage tolerance cannot create missing inventory; split the trade or wait for a new quote only if the resulting total cost still suits you.
The Amount Received and Gas Determine Cost
The relevant price is the output you receive for the input you give, after any spread or fee reflected in the quote. Ethereum gas is a separate cost paid in ETH, and its value changes with execution gas used and the effective gas price at inclusion. A token approval, when needed, may be a separate transaction with its own gas cost.
For an illustrative $1,000 USDC-to-WETH trade, suppose the reference price is $2,500 per ETH and the quote returns 0.3988 WETH. That output is worth $997 at the reference price, a $3 difference before gas. If execution uses 140,000 gas at an effective 10 gwei, gas is 0.0014 ETH, or $3.50 at that same reference price; the combined illustrative difference is $6.50.
Compare routes using the same input amount and an estimate of their net output, not the largest WETH figure alone. In that example, a route returning 0.3992 WETH but costing $8 in gas leaves about $990 of value, versus about $993.50 for the first quote. These are example figures, not Fermi fees or live prices; the useful comparison changes with trade size and network demand.
Approval and Minimum Output Set the Trade’s Boundaries
An ERC-20 input generally needs an allowance for the contract that will spend it. You can usually approve the intended trade amount rather than an unlimited amount, then authorize the swap itself. Before signing, check the token contract address, the spender, the amount and the receiving address in your wallet; a familiar token symbol alone does not identify the correct contract.
Minimum output translates a changing quote into a limit you can enforce. For example, a 0.5% tolerance on a quote of 0.3988 WETH gives a minimum of 0.396806 WETH. For a liquid major pair, 0.1% to 0.5% is a reasonable range to consider, but a tighter bound may fail during a fast move and a wider one permits a worse fill. Where a deadline is available, a short window such as 5 to 30 minutes limits how long an unsettled trade remains eligible.
A successful approval only changes permission; it does not complete the exchange. If a swap fails, check whether the quote moved below your minimum, the allowance or balance was insufficient, or the maker no longer had a usable fill. Repeatedly submitting the same trade without checking the cause can spend more gas without changing the outcome.
A Final Review Leads to Settlement
For an Ethereum Fermi swap, start with the exact input and output token contracts and confirm that both are the Ethereum assets you want. Keep enough ETH for gas, enter the amount you intend to sell, then compare the quoted output with your reference price and any alternative you are considering. Set a minimum you would still accept before authorizing the necessary allowance and trade.
After submission, use the transaction receipt and token transfers to confirm what happened. A pending transaction is not a completed exchange, and a wallet may take time to display a token it has not indexed before. The on-chain receipt and the balance at your address give a firmer answer than the wallet’s activity label.
For an occasional trade, the deciding figure is the minimum output you can accept after accounting for gas. At that point, Fermi swap lets you exchange the selected tokens directly from your wallet. An Ethereum Fermi swap is complete when the transaction confirms and the output token has reached your address.