From cold outreach to LOI. The conversion math of mid-market PE sourcing.

The honest funnel.

Working from the published 2024–2026 benchmarks and applying them to the specific dynamics of PE-add-on sourcing, the rough conversion math looks like this:

• Universe → Touched. 100% if the engine actually covers the universe. Most teams hit 12–15%.
• Touched → Engaged. Industry-average cold-email reply rate is 3.43%; top-decile is 10%+; signal-anchored campaigns reach 6–8%.^[1][4]
• Engaged → Warm conversation. Of the prospects who reply, roughly 35–50% in B2B contexts convert to an actual scheduled conversation if a multi-channel cadence is in place.^[4]
• Warm conversation → Qualified. Maybe 50–60% of warm conversations qualify as a real fit on the buyer’s criteria.
• Qualified → NDA / data room. Roughly 40–50% of qualified targets move into a formal information-exchange stage.
• NDA → IOI. Roughly 30–40%.
• IOI → Signed LOI. Roughly 30–50%.
• LOI → Close. Roughly 70–85% in mid-market PE, with variance based on diligence outcomes and financing certainty.

Stacked together, the universe-to-close conversion lands somewhere between 0.05% and 0.3% depending on signal quality, sector, and execution. That spread — six times difference between low and high end — is where sourcing operations either thrive or fail.

The arithmetic that matters.

Take a thesis with 2,000 viable targets. At the low end of the funnel (0.05% universe-to-close), that produces one closed transaction. At the high end (0.3%), it produces six. The difference is not the target list. The difference is everything that happens between the email and the LOI.

The lift from 0.05% to 0.3% comes from a small number of compounding inputs:

Signal-anchored outreach.

Reply rates jump from ~3% to ~6–8% when the first message references a specific, observable event at the target company.^[4] That doubles the top of the funnel.

Multi-channel cadence.

A structured 3-touch sequence (call + email + call) produces ~35% meeting-booked rates against single-touch attempts at half that.^[4] Bridge Group benchmarks show 80% of B2B deals require five or more touches, but 44% of reps stop after one.^[5] The compounding effect of running 8–12 touches is large.

Universe coverage.

A team that touches 2,000 targets at industry-average conversion produces ~1 LOI. A team that touches 200 targets at the same conversion produces 0.1 LOIs. The universe coverage variable dominates everything else.

Qualification discipline.

Conversations that don’t fit the thesis consume bandwidth without producing pipeline. The teams running real funnels are aggressive about disqualifying early. The teams that aren’t spend most of their time on conversations that go nowhere.

What this implies about staffing.

An honest read of these conversion rates suggests that a sourcing function targeting 3–4 LOIs a year from a thesis universe of 2,000 needs to be running at the high end of the funnel — signal-anchored, multi-channel, universe-complete. A team running average-execution math against the same universe will produce roughly one LOI a year and probably miss their deployment targets.

That doesn’t mean “hire more SDRs.” A five-person SDR pod running average-execution math is still average-execution math, just at higher cost. The lift comes from the infrastructure layer — signal detection, multi-channel orchestration, deliverability discipline, qualification rigour — not from incremental headcount.

Outbound SDRs at industry average produce ~21 meetings booked per month.^[3] Most of those meetings, in a PE context, don’t become qualified opportunities. The sourcing functions that consistently close add-ons are the ones that have stopped optimising for meetings booked and started optimising for the conversion ratio at every stage.

The summary.

Universe-to-close conversion in mid-market PE sourcing is somewhere between 0.05% and 0.3%. The number isn’t mysterious. The question is which end of that range a given operation lands on — and that question is answered by infrastructure, not by effort.