Spam
MEV
Speculative probes that search for MEV on-chain at execution time, consuming around a quarter of blockspace while rarely producing a trade.
Why does spam emerge? What does it cost?
And what can blockchain designers do about it?
Block gas
67% spam
1 / 36 found a trade
Two kinds of MEV extraction
Traditional MEV identifies opportunities off-chain and submits precise transactions. Spam MEV floods the chain with speculative probes whose profitability is resolved only at execution time.
Targeted MEV
Precise, computed off-chain. One transaction.
Losing bids filtered out before execution
Spam MEV
Speculative, resolved on-chain. Many probes.
Failed probes still consume block gas
Three conditions that enable spam MEV
$0.001
Low transaction fees make failed probes cheap
<1s
Fast block times leave no time for targeted extraction
No mempool?
Without a mempool, targeted extraction is harder
The spam equilibrium
As block capacity grows, spam enters and claims an increasing share of each additional unit. The model identifies three regimes depending on how capacity compares to demand.
Parameters use the paper's defaults: D₀ = 1200, β = 6, s = 20, r₀ = 6000, g_min = 20.
1,200
Block composition
Gas price?
29.2
Spam share?
14.6%
Spam txs
8.8
User welfare?
87.5K
−10% vs no-spam
Spam equilibrium across all block sizes
Blue area shows user gas, red area shows spam gas stacked on top. As capacity grows beyond the congested regime, added capacity increasingly serves spam until the plateau (B_plat = 1350) where both level off.
Three levers to reduce spam
Blockchain designers can adjust block capacity, set a minimum gas price floor, and choose transaction ordering. Each lever trades off spam reduction against user welfare.
Transaction ordering
Block composition with current settings
Spam share
9.3%
Gas price
48.8
Spam reduction
--
vs g_min=1
Monad's approach
Monad launched with a non-trivial minimum gas price and charges based on gas limit rather than gas consumed. Spam transactions reserve large gas allocations but use only a fraction when they fail; charging for reserved gas directly targets this asymmetry.
The favorable tradeoff
The share of each marginal unit of capacity going to users is strictly decreasing. Near the plateau, most additional capacity serves spam. Capping B_max before that point eliminates disproportionate spam at a small cost to user welfare.
User share of marginal block capacity as B_max grows. The curve drops toward zero near B_plat: each additional unit of capacity increasingly serves spam rather than users.