Convertible securities overview for founders

Convertible securities overview work is how early-stage founders raise cash now and settle ownership later. The instrument is usually a SAFE or a convertible note. Both postpone the hard valuation fight until a priced round, and both create real obligations on your Cap Table today. This post is the wide map: vocabulary, recording habits, conversion day, and stack rules. It is not the deep SAFE-versus-note decision guide. It is not legal, tax, or accounting advice. Ask counsel before you issue, amend, or convert anything.

Convertible securities overview: what the word means

A convertible security is a contract that can become equity later under rules you sign now. You take money. The investor gets a claim that converts into shares at a future financing (or another trigger your counsel defines). Until conversion, the Cap Table usually shows an instrument row, not common stock. After conversion, Scenarios and Overview must reflect the new shares.

Convertible is not the same as "informal." Y Combinator's SAFE materials (checked 31 Oct 2026) still expect board approval to issue SAFEs and say SAFE investors should be accredited. Neither a SAFE nor a note is a handshake.

For the instrument choice itself (interest, maturity, seniority, when a note still fits), read Convertible note vs SAFE for founders when that post is live on the public blog, and use SAFE note explained for startups for SAFE mechanics. This overview will not reteach that comparison table.

Where convertibles sit beside a priced round

Think in three layers. Layer one is cash-in convertibles (SAFE or note) that you record as instruments. Layer two is the priced equity round where those instruments convert under their PDFs. Layer three is ongoing Cap Table hygiene so Overview fully diluted totals match the closing binder.

Priced equity sets a price per share now and uses full preferred paperwork. Convertibles defer that price fight. Your job as an operator is to keep every outstanding convertible visible, modeled in Scenarios, and identical in CRM wording until conversion day. Mixing informal side letters that never reach Documents is how Overview and the PDF diverge.

Operator checklist table (not an instrument bake-off)

This table is about operating sequence. It deliberately avoids a SAFE-versus-note feature matrix so readers who need that bake-off go to the comparison post and the SAFE primer instead of seeing the same rows twice.

Terms to log without a second deep dive

You still need a short glossary so Cap Table fields get filled. Valuation cap and discount show up on many SAFEs and notes; conversion rules say which applies. MFN can change older paper when newer terms are richer. Notes add interest and maturity. Pro rata or information rights belong in the instrument or a filed side letter, not in Slack.

Do not negotiate a trophy cap for one angel without modeling dilution across the stack. Do not quote ownership in a board update until you know whether each SAFE is pre-money or post-money. When you need the commercial fight explained at length, leave this page for the SAFE primer and the note-versus-SAFE comparison rather than pasting their explanations here.

Model material checks in Cap Table Scenarios before Docs out. Save the Scenario with the investor name and date so you can show the board why you passed or accepted.

Illustrative conversion-day walkthrough (composite only)

The walkthrough below is a composite illustrative example, not a real raise and not a substitute for counsel's spreadsheet.

Illustrative setup: A company has two post-money SAFEs on Cap Table Equity instruments, each with a valuation cap, signed PDFs in Documents, and matching CRM deals marked Won only after wires cleared. Months later the company prices a Series A. On conversion day, counsel prepares the share counts. The founder opens Cap Table, uses the Conversions flow for each note or SAFE as the product allows, adds the resulting preferred (or other) shares, and confirms Overview fully diluted totals match the closing binder. Scenarios that were used to socialize ownership last week get archived or relabeled so nobody treats pre-conversion math as current truth.

Illustrative checklist the same afternoon: every converting instrument has a Conversions record or equivalent equity row, Documents still hold the original SAFE or note, the new stock purchase paperwork is filed, and Fundraising CRM Notes on those deals mention the conversion date. The illustrative point is sequencing: signed instrument, money in, Cap Table row, then conversion paperwork that updates the same system of record. Skipping the middle row is how ownership fights start.

Record instruments the same day money clears

On Cap Table (checked 31 Oct 2026), add the investor stakeholder, Create Instrument for the SAFE or convertible note, and record principal, discount, and valuation cap as the form requires. Keep board consents and the executed PDF on Documents. Glance at Overview for issued, authorized, and fully diluted shares after every change. Export All Data (JSON) when a cluster of convertibles closes so diligence is not inbox archaeology. Import All Data restores a backup later; treat exports as dated snapshots after each close cluster.

In Fundraising CRM, keep Fundraise Target honest and mark Won only when money meets your close definition. Attach the signed instrument under the deal's Files tab. Lost (passed) stays for people you declined; do not park convertibles in a soft stage after the wire.

Investor Readiness will not convert paper for you. It will show whether The Ask & Round Terms and Data Room still look empty while you claim you are raising on SAFEs. Fix Not yet gaps before you treat Ready to raise as a marketing line.

For ownership vocabulary around the ledger itself, see What is a startup cap table. Keep the SAFE primer linked above as the deep dive on SAFE forms; keep this page focused on the operating spine that any convertible shares.

Stack rules that belong on the overview

Convertibles help when speed matters and both sides accept floating ownership until a priced financing. They stall you when Scenarios look ugly, when note maturities bunch up, or when every angel wants a custom side letter. Count the specials already out before you celebrate a new verbal yes. If three custom side letters already exist, the fourth is a process smell, not a win.

Write a stack rule in a shared note: how many instruments, what caps are already out, who must approve the next one, and a hard ceiling on ownership Scenarios may show as sold on convertibles before a priced round is mandatory. Enforce the rule in CRM before Docs out. Review open convertible deals every Monday so signature chases and note maturity warnings do not hide under product work. When the ceiling is near, stop Docs out on new convertibles even if the pipeline looks hungry.

Calendar hygiene without a second comparison essay

If any convertible note is outstanding, put maturity dates on a shared calendar with a 60-day warning. Confirm whether interest is simple or compound and whether Cap Table principal needs an update before Conversions. For MFN, require a counsel check logged in CRM Notes before you issue richer terms. For the fuller note-versus-SAFE tradeoffs, use that comparison post when it is published rather than expanding this overview into a duplicate.

An illustrative habit: a quarterly thirty-minute review of every open convertible row against the signed PDF, even when no raise is active. That habit is about file integrity, not about choosing instruments.

Counsel, board, and what you say externally

Counsel drafts and negotiates. Founders file and narrate. Board consent belongs next to the signed PDF even if the board is just founders today. Externally, say instrument type, and quote cap or discount only if you mean to disclose them. Never quote ownership percentages that Cap Table Overview does not support.

If an investor asks for a quick convertible on terms you have not modeled, pause. Run Scenarios. Read the PDF. Then Approve & send follow-ups only for the process you actually intend. Keep amount, instrument, and timeline identical in every note. When terms change, update Notes and Cap Table instrument fields the same day counsel finalizes the PDF.

Say the instrument name the same way in the deck footnote, the CRM deal type, and the Cap Table instrument label. Precision is part of a convertible securities overview, not pedantry.

Convertible securities overview discipline is boring on purpose: name the instrument, log the terms that move ownership, file the PDF, mirror Cap Table, convert with counsel when the priced round arrives, and send readers to the SAFE deep dives for form choice. Do that and the next raise starts from a ledger instead of from folklore.