What is Gas fees?

A gas fee is the payment made to a blockchain’s validators to include a transaction in a block. On Ethereum and the chains built like it, every operation costs a fixed amount of gas, and the price of gas moves with demand: a simple transfer is cheap, a complex DeFi interaction costs more, and both cost far more when the network is busy. The fee is paid in the chain’s native token, ETH on Ethereum, and it is spent whether or not the transaction succeeds.

Since the London upgrade, an Ethereum fee has two parts: a base fee that the network sets and burns, and a priority tip that goes to the validator. The base fee rises when blocks are full and falls when they are not, which is why gas is predictable within minutes and unpredictable across days. Layer 2 networks exist largely to make this cheaper, batching many transactions into one Ethereum settlement and charging a fraction of the cost.

Gas is a real expense in portfolio terms. A wallet that has made hundreds of transactions has spent a meaningful amount of ETH on fees, and that spend is a cost of the activity, not a market loss. Several tax jurisdictions treat fees on a purchase as part of its cost basis and fees on a sale as a reduction of proceeds.

TrueHold reads transaction history with its fees from the chain, so gas spent shows in the history of the wallet and in the ledger that the export is built from, rather than disappearing between balances.

Chains outside the EVM name the same thing differently. Solana charges small fixed fees plus optional priority tips, Bitcoin charges by transaction size in bytes against a fee rate, and TON charges gas in Toncoin. Whatever the name, the fee is paid in the native asset, which is why a wallet needs a little of it to do anything at all.