Transaction Fees are fees charged by a blockchain network to execute and validate transactions on that blockchain network.
Fees are used to incentivize miners to complete complex and expensive cryptographic problems to validate transaction blocks to the leger of a blockchain.
As crypto adoption increases across decentralized finance and payments, networks get more congested with users and transactions, leading to longer wait times for getting transactions confirmed.
This leads some traders to pay higher fees per transaction in an effort to get miners to validate their transaction first, over transactions offering lower fees.
The higher the fee the faster a block is validated and added to the blockchain.
Transaction fees tend to collapse after large market sell-offs, as active addresses and the number of transactions on a network drop.
To this fact, many cryptocurrency analysts keep a close eye on changes in transaction fees over time as an indication of increased or decrease retail market participant interest.
3rd party analytics firms, such as Messari, maintain historical records and charts of the changes in average transaction fees for a given network, since the inception of that network.
For example, the average bitcoin (BTC) transaction fee for the last 30 days is USD $1.32
You can view more statistics and data about Bitcoin fees provided by Messari here.