Key Takeaways
- A bridge round is capital raised between priced rounds to reach a specific milestone — it is not a smaller version of the next round
- Bridges are almost always papered as a post-money SAFE or a convertible note, because a priced round costs weeks of negotiation and legal fees a bridge cannot carry
- Existing investors go first. A bridge with no insider participation tells outsiders that the people with the most information declined
- Size to a milestone plus margin, not to a number of months — "nine months of runway" is not a thesis, "nine months to a signed enterprise reference and a repeatable sales motion" is
- An MFN clause lets an early bridge investor take the best terms you grant later, so stacking MFN instruments can quietly give every holder your worst-case terms
- A bridge is still a securities offering — in the US typically under Rule 506(b) or 506(c) of Regulation D, with a Form D filed within 15 days of the first sale
- Model the entire instrument stack before signing: the bridge converts at the priced round alongside every earlier SAFE and note, all at once
A bridge round is capital raised between priced rounds, usually on a post-money SAFE or a convertible note, to fund a specific milestone that will make the next priced round raisable. Approach existing investors first, size the round to a milestone rather than to a number of months, and model how the new instrument converts alongside your existing SAFEs and notes before you sign anything.
The word "bridge" does real work. If you cannot name the far bank — the specific, verifiable thing that will be true when the money is spent — you are not raising a bridge. You are raising runway, and runway is not a thesis an investor can underwrite.
What Is a Bridge Round?
A bridge round is interim capital between two priced rounds, raised on convertible paper and converted at the next priced round's terms.
The mechanics are deliberately light. Rather than negotiating a valuation, a new class of preferred stock, board composition and protective provisions, you raise on an instrument that defers all of it to the next priced round. In practice, one of two documents:
Both convert into equity when you price the next round, subject to a valuation cap, a discount, or both. Neither sets a valuation today, which is precisely why founders use them when the valuation conversation would be unproductive.
When Does a Bridge Make More Sense Than a Priced Round?
When a specific, near-term milestone will materially change how the next round is priced, and you do not have the runway to reach it.
That is the whole test. Three situations pass it:
Three situations fail it:
Bridge vs Extension vs Inside Round vs Down Round
These four get used interchangeably and they are not the same transaction — the differences determine who you can approach and what you have to disclose.
The distinction that matters operationally: a bridge and an extension set no new price, while an inside round and a down round both do. If the honest answer is that your price has fallen, convertible paper postpones the reckoning rather than resolving it — and a low cap on the bridge prices it anyway, just less visibly.
Which Instrument Should a Bridge Use?
Use a post-money SAFE unless an investor specifically requires a creditor claim or a hard deadline, in which case use a note.
The trade-offs:
Two clauses deserve specific attention:
How Much Should You Raise?
Size the bridge to the cost of reaching the milestone, plus enough margin to run the next raise from a position of choice — not from a target number of months.
The arithmetic has three inputs:
Resist sizing up because a lower number feels unimpressive. Every additional dollar converts later, alongside everything already on the stack. The cheapest bridge that genuinely reaches the milestone is the right one.
Who Funds a Bridge, and in What Order?
Existing investors first, then investors who passed on the last round for timing reasons, then genuinely new investors — in that order, and the order is not optional.
The reason is informational. Your existing investors have board materials, monthly reporting and direct knowledge of the business. They are the best-informed capital available. When they participate, a new investor reads that as confirmation. When they decline, a new investor reads it as a verdict, and no narrative you construct will fully offset it.
Within that order:
How Do You Raise a Bridge Without Signalling Distress?
Lead with the milestone and the insider commitment, give the number a reason, and never present the bridge as a response to running low on cash.
Concretely:
What Are the Legal Mechanics?
A bridge is a securities offering and carries the same exemption and filing obligations as the round before it.
In a US private bridge the offering is almost always made under Regulation D. Rule 506(b) permits sales to accredited investors and up to 35 non-accredited purchasers but prohibits general solicitation; Rule 506(c) permits public advertising but requires reasonable steps to verify each purchaser's accredited status, defined at 17 CFR 230.501. The rule text sits at 17 CFR 230.506. A Form D notice is filed within 15 days of the first sale — see the SEC's Form D guidance and 17 CFR 230.503.
Beyond the exemption, three housekeeping items:
Frequently Asked Questions
What is a bridge round?
A bridge round is capital raised between two priced equity rounds, almost always on convertible paper — a post-money SAFE or a convertible note — that converts into equity at the next priced round's terms. Its purpose is to fund a specific milestone that will make the next priced round raisable on better terms than it would be today. It sets no new valuation.
Is a bridge round a bad sign?
Not inherently. A bridge raised against a defined, near-term milestone with strong participation from existing investors reads as deliberate sequencing. A bridge raised because the company is running out of cash with no change in plan reads as distress. The signal comes from two things: whether there is a specific milestone, and whether the best-informed capital on the cap table is participating.
Should I use a SAFE or a convertible note for a bridge?
Use a post-money SAFE for most bridges. It has no interest, no maturity date and no repayment obligation, the standard forms are free and widely accepted, and the investor's ownership percentage is fixed at signing so your dilution is visible immediately. Use a convertible note when an investor specifically requires a creditor claim or a hard conversion deadline, and understand that the maturity date is genuine leverage against you.
How much should I raise in a bridge round?
Raise the cost of reaching the milestone, plus the cost of running the next round, plus enough margin that you are never negotiating a term sheet while out of cash. Avoid sizing up for appearances: bridge capital converts at the next priced round alongside every SAFE and note already outstanding, so each additional dollar compounds the dilution you take later.
Who should I approach first for a bridge?
Existing investors, before anyone else. They have the most information about the business, so their participation is the strongest validation available and their refusal is the most damaging data point. Approaching new investors before you know where your insiders stand creates a signal you cannot retract if the insiders then decline.
Does a bridge round require an SEC filing?
In a US private offering under Regulation D, yes — the issuer files a Form D notice with the SEC within 15 days of the first sale. The bridge is a securities offering in its own right, so it also needs an available exemption, typically Rule 506(b) or Rule 506(c), and the choice between them governs whether you may publicly advertise the raise and how you must verify investor accreditation.
The Bottom Line
Name the milestone, size the round to reach it, and secure your insiders before you talk to anyone else. A bridge with a defined far bank and insider participation reads as sequencing; one raised for runway alone reads as distress, and the market rarely gives you a second reading.