MEV‑Share vs Private Relays: When to Use Each

Overview

Both paths have trade‑offs. Start with simulation and measure outcomes.

Use MEV‑Share when

• Information sharing is acceptable and privacy needs are moderate.
• You want specific matching flows.

Use private relays when

• You need minimal information leakage and want to avoid PGAs.
• You have strong inclusion with selected relays.

Guardrails

• Slippage and gas caps; session budgets.
• Clear fallback logic.

Privacy and control

MEV‑Share exposes hints to builders to increase match rates. That can be useful when you want specific order flow, but it leaks some strategy data. Private relays keep payloads sealed until they hit the builder. FRB defaults to private bundles so you retain control, then lets you enable MEV‑Share lanes for canaries or niche flows.

Inclusion expectations

• MEV‑Share: inclusion depends on builder attention and the attractiveness of your hints. Expect variable latency.
• Private relays: inclusion is tied to builder uptime and your relationship. Measure p50/p95 across several relays and rotate proactively.

Workflow recommendation

1. Simulate both lanes for at least 24 hours each.
2. Compare inclusion ratios, refunds, and latency using Ops Pulse.
3. Assign guardrails: run private bundles by default, MEV‑Share as a purpose-built route.

Evaluation matrix

Walk leadership through this table so the trade-offs are explicit before you flip any switches.

Reporting pack

• Daily: spend vs refunds per lane, notable incidents, guardrail triggers.
• Weekly: inclusion delta, latency histograms, documentation links.
• Monthly: decision log—who approved MEV‑Share usage, why, and whether KPIs justify continuing.

FAQ

Can I run both at once?
Yes. Keep budgets separate so one path cannot drain the other.

How do I document the choice?
Link to this article from your internal runbook and note who approved MEV‑Share usage.

What if a relay fails?
Fall back to your MEV‑Share lane, but log every attempt and scale size down to canary levels.

How do I prevent hint abuse?
Throttle the granularity of your hints, rotate keys frequently, and monitor builder behavior. If fills look suspicious, cut the MEV‑Share lane immediately and escalate.