The Invisible Users of DeFi

If arbitrage bots are the most visible form of programmatic trading, solvers and searchers are the least visible — and often the most important.

By Jamie McCormick, Co-CMO, Stabull Labs

The eighth article in the 15 part “Deconstructing DeFi” Series.

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They do not chase small price discrepancies in isolation. Instead, they focus on constructing optimal execution paths across many protocols at once. In the transactions we traced on Stabull, their presence was subtle but unmistakable.

Understanding solvers helps explain why Stabull liquidity is being used in ways that don’t resemble traditional “trading” at all.

What solvers and searchers actually are

A solver is a system that takes a trading intent and determines the most efficient way to fulfil it.

The intent might be:

• “Swap asset A for asset B”
  
• “Rebalance a treasury”
  
• “Settle a complex order with minimal slippage”
  

The solver’s job is not to trade one pool, but to design the entire execution.

Searchers are closely related. They scan the chain and mempool for opportunities to construct profitable or efficient transactions, often competing with other searchers to submit the best possible execution.

How solver-based execution works

Rather than relying on a single venue, solvers:

• simulate multiple possible execution paths
  
• combine swaps across different protocols
  
• account for fees, slippage, and gas costs
  
• choose the path that best satisfies the objective
  

All of this happens before the transaction is submitted on-chain. Once executed, the transaction runs atomically.

From the chain’s perspective, the result is a single transaction touching many protocols in sequence.

Why solvers exist in DeFi

DeFi’s strength is composability. Its weakness is fragmentation.

Liquidity is spread across:

• different DEXs
  
• different pricing models
  
• different asset specialisations
  

Solvers exist to stitch this fragmented landscape together. They turn many local optimisations into one global outcome.

As DeFi matures, solver-driven execution becomes more common, not less.

Why solvers care about execution quality

Solvers are ruthlessly objective.

They do not care:

• which protocol is “popular”
  
• which team is active on social media
  
• which pool launched most recently
  

They care about:

• predictable pricing
  
• reliable execution
  
• minimal slippage
  
• atomic safety
  

A pool that fails any of these criteria is simply excluded from execution paths.

Where Stabull fits into solver flows

In the transactions we reviewed, Stabull appeared as:

• a stable execution leg
  
• an FX conversion point
  
• a price anchor for RWA-backed assets
  

Because pricing is oracle-anchored, solvers can treat Stabull pools as deterministic components inside a larger execution plan.

This makes Stabull useful even when it is not the cheapest venue in isolation. Reliability and predictability often matter more than marginal price improvement.

Invisible volume, strong signal

Solver-driven volume is easy to miss because it rarely appears dramatic.

Trades are often:

• medium-sized
  
• frequent
  
• tightly optimised
  
• repeated under similar conditions
  

There are no spikes, no hype, and no obvious “users.”

But this is precisely why it is such a strong signal.

When solvers include a protocol in their execution logic, they are effectively endorsing it as infrastructure.

Solvers versus arbitrage bots

Although both are automated, solvers differ from arbitrage bots in intent.

Arbitrage bots react to price differences.

Solvers proactively design execution paths.

Arbitrage corrects markets after they move.

Solvers prevent inefficiency before it appears.

In practice, both often interact within the same transaction.

Why this matters for Stabull

Solver usage indicates that Stabull is no longer being evaluated purely as a swap venue.

It is being evaluated as:

• a reliable pricing source
  
• a low-risk execution component
  
• a building block inside more complex systems
  

This kind of usage compounds naturally as more protocols and execution systems come online.

In the next article, we’ll look at how aggregators take these same execution capabilities and distribute them to end users at scale — often without those users ever knowing which protocols were involved.

About the Author

Jamie McCormick is Co-Chief Marketing Officer at Stabull Finance, where he has been working for over two years on positioning the protocol within the evolving DeFi ecosystem.

He is also the founder of Bitcoin Marketing Team, established in 2014 and recognised as Europe’s oldest specialist crypto marketing agency. Over the past decade, the agency has worked with a wide range of projects across the digital asset and Web3 landscape.

Jamie first became involved in crypto in 2013 and has a long-standing interest in Bitcoin and Ethereum. Over the last two years, his focus has increasingly shifted toward understanding the mechanics of decentralised finance, particularly how on-chain infrastructure is used in practice rather than in theory.