Priced rounds are now first-class citizens in the Arx pro-forma module.

For most of Arx's first year, the pro-forma engine supported SAFE conversions and post-money-SAFE math but stopped short of full priced-round modeling. That gap mattered: any founder running the math on a $4M seed at a $20M post-money premium had to export to a spreadsheet, do the option-pool top-up by hand, and reconcile by eye.

That ends today. The pro-forma module now models a priced round end-to-end.

What's new.

  • Pre/post-money input flow. Toggle between pre and post; the other recomputes live as you change the round size.
  • Option pool top-up. Set a target post-round pool percentage; Arx calculates the top-up amount, the dilution borne by existing shareholders, and the new pool share count.
  • Lead participation. Define the lead's check size and their pro-rata claim; Arx layers the other investors against the remaining allocation.
  • SAFE conversion math. Any outstanding SAFE on the cap table now converts in the pro-forma using each SAFE's own valuation cap and discount terms — including post-money-SAFE math, which is more punishing than founders sometimes expect.
  • Side-by-side scenarios. Save up to four parallel scenarios — different round sizes, different pre-money valuations, different pool top-ups — and compare founder ownership, investor ownership, and pool dilution across all of them.

How to use it.

From the Forecast & pro-forma module, open the cap table, click "New scenario," and choose "Priced round" as the instrument. Enter the round size, the lead, and the participants. The pro-forma renders the full waterfall — pre-existing common, prior SAFEs converting, the new pool, the new investors — in seconds.

A pro-forma is most useful before the term sheet conversation, not after. Sharing it with your lead pre-term-sheet often saves a week of back-and-forth on numbers everyone already agrees on.

Why we shipped this.

Two reasons.

First, the founder reality: more than a third of the seed rounds we tracked across our user base in Q1 2026 were priced, not SAFE-only. The "SAFEs for seed, priced for A" pattern is no longer the dominant arrangement. Many seed rounds in the $3–5M range are priced today, often because a lead requires it for board-seat math. Building pro-forma in Sheets is a tax on those founders.

Second, the consistency reality: when the cap table, the forecast, and the pro-forma all live in the same workspace, you do not have to re-enter the SAFE valuation cap in three different places. One source of truth. One write, one update.

What it does not do (yet).

Two things we explicitly chose not to ship in this release:

  • Series A and later priced rounds. The current release is tuned for the seed and seed-extension life stage. Series A modeling — with multiple share classes, anti-dilution clauses, and full liquidation-preference modeling — comes in a separate release later this quarter.
  • 409A integration. Some founders asked. We will not be shipping 409A workflows ourselves. Carta and several other tools do this well, and we'd rather export cleanly to them than ship a half-version.

Pricing.

The priced-round pro-forma is part of the existing $99/month Arx plan. No upgrade, no add-on, no per-scenario fee. The plan continues to include unlimited seats.

Try it.

Existing customers: the new instrument shows up automatically in any new scenario you create. No migration required.

New: start a 14-day trial and import your existing SAFEs as the first scenario.

We will publish a follow-up piece in two weeks on what the most common priced-round shapes at seed actually look like in the data we now see — pre-money distributions, pool-top-up norms, founder dilution ranges. If you would like to be on the early-access list for that piece, the newsletter signup is at the bottom of the Writing index.