Bridge Round

A bridge round is interim financing raised between two priced rounds, typically a SAFE or convertible note that extends runway to a specific milestone. It is raised between two larger priced rounds (or before the company's first priced round), structured as a SAFE or convertible note rather than a new priced equity round, designed to extend a startup's runway long enough to reach a milestone that unlocks the next priced round on better terms than would have been possible without the bridge. The discipline that distinguishes a useful bridge from a "bridge to nowhere" is the milestone: a clear, near-term proof point that materially changes the next round's terms.

The 2025 bridge round patterns:

Bridge type	Typical size	Typical instrument	Common purpose
Pre-seed → seed	$250K-$1M	SAFE	Hit MRR/user milestone for seed
Seed → Series A	$500K-$3M	SAFE or note	Hit ARR milestone for A
Series A → Series B	$3M-$10M	Note (often)	Hit ARR/growth milestone for B
Pre-IPO bridge	$20M-$100M+	Late-stage convertible	Extend runway through IPO window
Distress bridge	Varies	Notes with structure	Avoid running out of cash; pursue exit

Who funds bridge rounds:

Existing investors (most common): the lead from the previous round protects their position by funding the bridge. Often a "pro-rata-plus" round where existing investors take their pro-rata plus some incremental.

New investors entering quietly: sometimes a bridge is structured as a small entry-point for a new investor who wants to lead the next priced round, betting on the company hitting the milestone.

Strategic investors: corporate venture or strategic partners sometimes bridge companies in their ecosystem.

Venture debt: not technically a bridge round but often serves the same purpose; non-dilutive but with covenants and interest. Common 2023-2025 as equity got harder.

The bridge-to-nowhere problem:

The distinguishing feature of a bridge to nowhere:

• No clear milestone that the bridge unlocks. The company is buying time hoping something changes.
• Existing investors funding alone, on softer terms: signals that no new investor sees a deal at the next round.
• Declining metrics since the previous round: growth slowing, churn rising, runway shrinking faster than expected.
• Structure on the bridge instruments (1.5x preferences, ratchets, MFN): existing investors getting protection because they don't trust the milestone story either.

When a bridge IS the right move:

• Specific milestone clearly defined (e.g., $2M ARR for Series A, ship product version 2.0 for B, close 3 anchor enterprise customers).
• Realistic timeline to milestone (6-9 months for most bridges; longer is harder to justify).
• Clear path to better terms with the milestone in hand.
• Existing investors confident enough to lead the bridge with reasonable terms.

The structure terms in 2025:

Most bridges are:

• Post-money SAFE with a cap that's a discount to the previous round's valuation (commonly 80-90% of previous post-money).
• Or convertible note with 4-8% interest, 18-24 month maturity, conversion at next priced round with discount (15-25%) and cap.
• Sometimes priced with new pricing if the bridge is large enough and the price difference is material.

What founders get wrong (specific failure mode): Company raises a $2M bridge SAFE 18 months after seed because they haven't hit the Series A bar. Founder believes the bridge "buys 9 months" to get to A. But the underlying growth problem (slow sales pipeline, poor conversion, weak retention) hasn't been diagnosed or addressed. Nine months later, the company still hasn't hit the bar, ARR has grown from $400K to $550K (modest), and now needs another bridge or faces a distress sale. The first bridge bought time but didn't fix the problem; the second bridge is much harder to raise. The right discipline: diagnose what's broken BEFORE raising the bridge; bridge only if the diagnosis is clear and the path to fix is concrete; if you can't diagnose, the bridge is just a delay mechanism.

Related: Seed Round · SAFE · Convertible Note · Down Round · Extension Round · Runway

FAQ

What is a bridge round in startup funding?
Interim financing raised between two larger priced rounds (or before the first priced round), typically structured as a SAFE or convertible note, designed to extend runway until the startup reaches a specific milestone that unlocks the next priced round on better terms.

Is a bridge round a bad sign?
It depends entirely on the milestone. A bridge to a clear, near-term milestone is a normal tool. A "bridge to nowhere", buying time without a defined milestone, is a warning sign. Investors and acquirers read which one a bridge represents based on the underlying metrics and milestone clarity.

How is a bridge round structured?
Most commonly as a post-money SAFE with a cap (typically 80-90% of previous post-money) or a convertible note with 4-8% interest and 18-24 month maturity. Both convert at the next priced round with discount (15-25%). Distress bridges sometimes have additional structure (preferences, ratchets, MFN).

What's the difference between a bridge round and an extension round?
A bridge round explicitly bridges to a future priced round. An Extension Round adds to an existing priced round at the same terms (often shortly after the round closed). Mechanically similar; semantically different.