What is the gas fee? In the blockchain world, the gas fee is a fee that users have to pay to the blockchain network for each transaction. For example, when a user makes a transfer on Ethereum, miners must package his transaction and put it on the blockchain to complete the transaction. This process consumes the computing resources of the blockchain, and the fee paid to miners is called the gas fee.
Imagine that each public chain is a society or a city, and gas would be the currency that users need for various activities in the city, and the economic designs of gas have far-reaching impacts on the public chain’s future development. Today, we will illustrate the significance of the gas economy from the perspectives of performance and value capture.
– The frequent network congestion of Solana
In early May, Solana’s mainnet lost consensus, and block generation was suspended for 7 hours. The mainnet was down due to the NFT minting of a new NFT project. Users turned to bots for sending transactions as much as possible to increase their success rate of minting. This led to 6 million transactions per second on the Solana mainnet, which jammed the network. Moreover, as Solana transmits consensus messages as a special transaction message between validators, the heavily congested network also disabled the normal transmission of consensus messages, eventually leading to the loss of consensus.
This is not the first downtime of Solana. Last September, the public chain suffered a 17-hour downtime due to the massive trading volume created by on-chain bots during the launch of the hit project Raydium. A 30-hour Solana downtime incident happened at the end of January 2022 when the BTC price plunged from $44,000 to $33,000 during a market crash and created plenty of arbitrage opportunities. Meanwhile, the liquidation/arbitrage bots on Solana, which center on DeFi, kept creating massive transactions, which resulted in network downtime. When comparing Solana to a conventional IT system, we can tell that the downtime resembles a DDoS attack.
「A DDoS (distributed denial-of-service) attack refers to adding traffic from multiple sources to exceed the processing capacity of a network so that real users would not be able to acquire the resources or services they need. Attackers often launch a DDoS attack by sending more traffic to a network than it can handle or sending more requests to an application than it can manage.」
Instinctively, many people would think that Solana’s downtime is rooted in its public chain designs: the monolithic design of Solana inevitably leads to downtime.
At the moment, mainstream public chains use two kinds of designs: the modular and the monolithic. The modular architecture refers to a modularized deployment where consensus, storage, and execution are implemented separately so that the collapse of the execution layer will not compromise the security of the consensus layer. At the same time, mainstream designs adopted by Avalanche’s Subnet, ETH 2.0, and Celestia’s Rollup can all diverge massive transactions. On the other hand, although Solana as a whole is designed to enable fast transactions, scalability and security were sacrificed.
However, the modular design of a public chain is not the key because although the consensus stayed secure, the individual rollup could still suffer from downtime when facing overwhelming transactions in a very short period. In other words, the modular design just lowered the systemic risks (e.g., a certain rollup could halt but the rest can survive) for the public chain. The gas design is the real reason behind Solana’s downtime, and more network downtime is on the way if the design is not improved.
– The gas mechanisms of different chains
The figure below shows the gas designs of three mainstream public chains. On Solana, the gas fee is based on the number of signatures. The more signatures a transaction uses, the higher the gas fee. However, the maximum memory capacity of each transaction is fixed, and so is the maximum gas fee per transaction, which helps users easily calculate the cost of sending massive transaction requests. Moreover, transactions on Solana are not sequenced, which means that when the cost of sending massive requests is lower than the profit (arbitrage, NFT minting, etc.), users would use bots to send transactions on a large scale to increase the likelihood of the execution of their transactions. This is also the reason behind the downtime events that took place on Solana.
Ethereum and Avalanche share similar gas designs. Both feature the base fee and the priority fee, which creates an inherent sequencing issue because transactions with a higher priority fee would be first executed. As such, although users can still use bots to create massive transactions on Ethereum and Avalanche, their transactions will not be executed no matter how many requests are sent when the priority fee becomes insufficient, and they have to wait in line. Considering the cost of gas, such a design eliminates the possibility of network downtime arising from massive transactions at the economic level.
– Improvement by Solana
Economic isolation has always served its purpose better than methodological isolation. Solana has already started to build its own Fee Market by introducing a concept similar to the priority fee. Meanwhile, Metaplex, Solana’s NFT market, will also adopt a new concept called Invalid Transaction Penalty, which means that users will have to pay a fee for invalid transactions when minting NFTs.
Value capture is the reflection of a gas economy via the market cap of the gas (the native crypto of the chain). The market cap of a native coin is roughly determined by two factors: cash flow and monetary premium.
– Cash flow
When it comes to charging the gas fee, most public chains follow the same approach: lower the gas fee as much as possible to attract users from Ethereum. From the perspective of cash flow, such an approach is unsustainable. Of the three mainstream public chains, only Ethereum stands with a considerable net cash inflow, although the network is still issuing more Ethers. If we consider additional issuance as a type of subsidy, then the net expenditure of Ethereum per day would be about $25.7 million if the annual issuance rate stands at 3.21%. Solana and Avalanche, on the other hand, have an income of $6,250 and $42,000 a day on average, with a daily net expenditure of $4.6 million and $1.86 million and a yearly issuance rate of 6.93% and 5.22%. The high net expenditure & high issuance rate significantly dilute the market cap of the public chain coins.
Let’s turn to the destinations of cash flows. Under Ethereum’s current mechanism, the base fee is burned, while the priority fee is offered to miners. Compared with the gas burning and distribution mechanisms of Solana and Avalanche that offer the gas fee to validators, the miner reward is a design that compromises value capture. Ethereum uses the PoW design for block generation, and most of the miners adopt a business model under which tokens that have been mined are sold to cover the mining cost (such as electricity fees and maintenance costs). Therefore, the part of the gas fee paid to miners will most likely go out from the ecosystem. It would be better to give the gas fee to validators because the cost of running a node is not as high as operating a mining factory. Since there are not significant ongoing operating cost, validators are more likely to invest the rewards they’ve received in the nodes, which makes the ecosystem safer without diluting the value of the native coin. Burning fees might be the most direct and effective way to capture valuee and benefits both node stakers and token holders. In addition, MEV constitutes another major source of revenue for public chains. According to statistics from Flashbots, from 2020 to now, $600 million worth of MEV has been paid to miners, which is a conservative estimate.
– Monetary premium
Monetary premium refers to the appreciation of a public chain coin in terms of its practical value and value storage. Most existing public chain coins are carrying out massive issuance, which makes them poor value storage, and the practical value forms the backbone of their market cap. The growth of the ecosystem of a public chain coin will create scenarios where it can be used as a payment method. For instance, most NFT transactions are settled with public chain coins. Meanwhile, most emerging public chains also consider the practical value as the primary means of appreciation, which is why they have set negligible gas fees to attract traffic and new users. Meanwhile, some public chains have built foundations worth hundreds of millions of dollars to encourage more developers to build DApps in their ecosystem. The logic behind such an approach is to make big investments to attract users in the initial stage and try to recover the cost later.
To sum up, the gas design of a public chain will have profound impacts on the future development of a public chain, and a poor design could lead to poor value capture and even performance bottlenecks. When evaluating a public chain project, we can also get a rough picture of its development strategy and future growth through its gas designs.