Bridge Round

A bridge round is interim financing raised between two major institutional rounds, typically ranging from $500,000 to $3 million.¹ It takes its name from the concept of bridging the gap between a company's current runway and its next priced funding event — such as a Series A or Series B.² Bridge rounds are usually structured as convertible notes or SAFEs rather than priced equity, deferring the formal valuation negotiation to the next round.³

Mechanics

Convertible Notes

A convertible note is a short-term debt instrument with an interest rate — typically 5–8% annually — and a maturity date, usually 18 to 24 months.⁶ If the company raises a qualifying priced round before maturity, the note converts into preferred stock at a discount to the new round's price.⁵ The discount (commonly 10–25%) and an optional valuation cap — a ceiling on the conversion price regardless of the actual round price — are the two key economic terms.¹

Interest accrues on the principal and either converts alongside the principal or is paid in cash at maturity or conversion.⁶ A $1 million note at 8% annual interest accrues $120,000 over 18 months, increasing the total amount converting to equity.¹

If the company does not raise a priced round before the maturity date, the note technically becomes due. In practice, companies typically extend the maturity date with noteholder consent, convert at an agreed valuation, or raise a new financing to repay the notes.¹ Convertible notes are classified as debt on the balance sheet, which can affect a company's ability to raise venture debt or a working capital line of credit.¹

SAFEs

A SAFE (Simple Agreement for Future Equity) is a newer instrument popularized by Y Combinator.¹ Unlike a convertible note, a SAFE carries no interest rate, no maturity date, and is not classified as debt on the balance sheet.⁶ When a qualifying priced round occurs, the SAFE converts to preferred stock at a discount or capped valuation.⁵

SAFEs close faster than convertible notes — sometimes within a single day — because they involve less legal overhead.¹ The absence of a maturity date removes the pressure of a hard deadline, but also means a SAFE could remain unconverted indefinitely if no qualifying round occurs.¹

Valuation Cap and Discount

Both instruments commonly include a valuation cap — a ceiling on the pre-money valuation used to calculate the conversion price.¹ If the actual round valuation exceeds the cap, bridge investors convert at the lower capped price and receive more shares per dollar than the new round investors. A separate discount may apply instead of or alongside the cap; investors convert at whichever term produces the lower price.¹

For example: a $1 million bridge with a $5 million cap converts at the $5 million valuation even if the Series A closes at $15 million. Bridge investors effectively receive a 67% discount relative to the new Series A price.¹

Why Companies Raise Bridge Rounds

Runway extension is the most common reason: a company has 6–8 months of cash remaining but has not yet reached the metrics required to attract a Series A on favorable terms.¹ A bridge buys additional time to hit milestones.

Valuation protection is a second motivation: market conditions may have softened or the company's growth stalled, making a full priced round likely to result in a down round. A bridge delays the valuation conversation until conditions may improve.¹

Investor signaling is a less common rationale: some companies raise a bridge from existing investors to demonstrate support before opening a broader round. This can backfire if the market interprets it as an inability to attract new investors.¹

According to venture data from 2023–2024, 60–70% of funding rounds included a bridge component, up from approximately 40% five years earlier — a normalization driven partly by the post-2021 venture capital slowdown.¹

Red Flags vs. Legitimate Use Cases

A single bridge round from existing investors is common and generally accepted by future investors.² Multiple sequential bridges — particularly from the same investors without new participation — signal difficulty raising a full round and can deter new Series A investors who encounter a complex cap table.¹ Some institutional Series A funds have internal policies about the maximum number of bridge rounds they will tolerate in a company's financing history.¹

Implications

Dilution

Bridge rounds dilute founders and existing common stockholders at conversion, not at issuance.¹ Because the dilution is deferred and depends on the next round's price, founders sometimes underestimate the true cost until the cap table is calculated after the Series A closes.¹

A $1 million SAFE with a $5 million cap converting into a $15 million Series A effectively purchases shares at a 67% discount to the new round price. If the founder had raised that $1 million as part of the Series A instead, they would have given up a smaller ownership percentage at the higher price.¹

Raising multiple bridges compounds the dilution effect. Each bridge adds a new row to the cap table with distinct conversion terms, and the cumulative impact across multiple bridges can materially reduce founder and early employee ownership by the time a Series A closes.¹

Pro-Rata Rights

Bridge investors typically receive pro-rata rights in the next priced round — the right to invest enough to maintain their ownership percentage.¹ If bridge investors are large existing shareholders, their pro-rata participation can absorb a significant portion of the Series A allocation, reducing the amount available to new investors and constraining the round size.¹

Bridge vs. Down Round

A bridge round is sometimes used specifically to avoid a formal down round, since convertible instruments defer the price-setting to the next priced round rather than establishing a new, lower price per share immediately.⁸ If the next priced round ultimately occurs at a lower valuation than the prior round, bridge investors may convert at the capped price — which could be lower than the prior round's price — producing a de facto down round through the conversion mechanics rather than a formal priced one.¹