Down Rounds, Bridge Notes, and Runway: What Founders Need to Know

When a startup raises funding at a lower valuation than its previous round, that’s a down round. When it needs cash to extend operations until the next financing event, it might use a bridge note. When investors or founders talk about how long a company can operate with its current cash, they’re discussing runway. These three concepts sit at the center of startup survival and failure.

Understanding each one matters not just for founders and investors, but for anyone trying to follow how startups actually operate at the moment they become financially fragile.

What a Down Round Is and Why It Happens

A down round occurs when a company raises capital at a lower per-share price than it did in an earlier round. If a startup raised its Series A at a $10 million valuation and later raises Series B at $8 million, that’s a down round. These transactions became more common during market downturns, when venture capital becomes scarce or expensive.

Why Valuations Fall

Down rounds result from misalignment between a company’s growth and investor expectations. A startup might have missed revenue targets, faced market headwinds, lost customers to competitors, or struggled to achieve the milestones it promised investors. Even well-run companies sometimes can’t raise at higher valuations because the total pool of available capital shrinks.

The Hit to Existing Shareholders

Existing shareholders—founders, employees with equity, and earlier investors—suffer financially in a down round. If you hold shares worth $10 million before a down round halves the valuation, your stake’s theoretical value drops. Some investors face dilution beyond the percentage they’d typically accept in a normal round. In worst cases, existing shareholders see their shares become worthless if the company continues declining.

Down rounds also trigger anti-dilution provisions in earlier investment agreements. These clauses protect earlier investors by adjusting their share count if later rounds happen at lower prices, a mechanism that can shift equity away from founders and employees toward earlier-stage backers.

Bridge Notes: The Short-Term Funding Band-Aid

A bridge note is a short-term debt instrument that fills the gap between now and the next financing round. Instead of raising equity immediately at an unfavorable valuation, a startup borrows money with the agreement that the loan will convert into equity once the next round closes. This structure lets founders buy time without giving away equity at depressed prices.

How Bridge Notes Work

A typical bridge note has a principal amount, an interest rate, and a maturity date. The startup owes both principal and interest when the note matures, usually 12 to 24 months out. Before maturity, if the company raises a new round of equity funding, the note automatically converts into shares of that round, typically at a discount to the new price.

Interest rates on bridge notes typically range from 5% to 10% annually, though the actual rate depends on the company’s creditworthiness and market conditions. Bridge notes also include a conversion cap: if the company raises Series B at a $50 million valuation but the bridge note has a $40 million cap, investors holding the bridge convert at the capped price, receiving more shares than they would have at the actual round price. The discount—often 20% to 30% off the next round’s valuation—compensates bridge investors for the risk they take by lending when valuations remain uncertain.

When Bridge Financing Makes Sense

Startups use bridge notes when they expect to raise a larger round within 18 months but need cash now. A company burning $500,000 per month with 8 months of runway might use a $2 million bridge note to stay operational for 12 months while its team fundraises. The conversion feature ensures that if fundraising succeeds, bridge holders automatically become equity investors, aligning their interests with the company’s success.

Bridge notes also appeal to early-stage supporters—founder friends, angel investors, or venture firms making a small check—who want exposure but aren’t ready to participate in a full priced round. Platforms like AngelList have made it easier for startups to access bridge financing from accredited investors without relying solely on early backers.

Runway: The Clock Every Founder Watches

Runway is the number of months a startup can operate at its current burn rate with its existing cash. If a company has $1 million in the bank and burns $100,000 per month, it has 10 months of runway. This number defines when the company must raise money or shut down.

How to Calculate It

Runway equals current cash divided by monthly burn rate. The burn rate includes salaries, server costs, office rent, marketing spend, and every other operating expense. Founders track this number obsessively because it determines their negotiating position in fundraising and sets a hard deadline for survival.

Runway isn’t static. A startup that cuts costs and reduces monthly burn from $300,000 to $200,000 extends its runway without raising capital. Conversely, hiring new engineers or launching expensive marketing campaigns shrinks runway faster. Some founders manage runway by combining cuts with new revenue, a combination that can dramatically extend the timeline before fundraising becomes unavoidable.

Why Runway Affects Fundraising Power

Runway determines a founder’s negotiating position in fundraising. A startup with 18 months of runway can afford to wait for the right investor and can reject unfavorable terms. A startup with 3 months of runway must raise immediately, often on whatever terms investors offer. Y Combinator, the startup accelerator, advises founders to raise new capital when they have 6 to 9 months of runway remaining, while they can still negotiate favorable terms rather than from a position of desperation.

How Down Rounds, Bridge Notes, and Runway Intersect

These three concepts often appear together in startup crises. A company raises Series A, burns through cash faster than expected, and suddenly has only 4 months of runway. It can’t raise a priced round at an attractive valuation, so it issues a bridge note to buy time. If the next round still comes at a lower valuation, the existing shareholders suffer a down round, and the bridge note holders convert at a favorable price, having taken less risk by arriving later.

In healthier scenarios, strong companies raise bridge notes as a tactical choice rather than a desperation move. They might raise $5 million in bridge notes while closing a $50 million Series B, using the bridge as a top-up to extend runway through a long product roadmap.

Terms and Hidden Costs of Bridge Financing

Bridge notes aren’t simple loans. Common terms include the interest rate, the maturity date, the conversion discount (20% to 30%), and the valuation cap. Some bridge notes include a most-favored-nation clause: if the next round closes at a better valuation or discount than the bridge terms offer, the bridge investor gets the better deal automatically.

The Dilution Math

Bridge note investors own actual shares once conversion happens, which dilutes the founder’s stake. A founder with 40% equity before raising a $2 million bridge note at a 25% discount might own 35% after conversion, depending on the company’s valuation and the number of bridge notes issued. This dilution compounds with each financing round.

Cap table management tools like Carta help founders track their ownership percentage and see exactly how dilution from bridge notes and down rounds affects their stake. Without precise tracking, founders can lose sight of how much of the company they still own.

When Conversion Fails

If a startup fails to raise a new round before the bridge matures, it owes the principal and interest in cash. For a struggling company, that’s often impossible, leading to negotiated extensions (the lender agrees to delay repayment) or conversion to equity at an emergency valuation. The bridge note becomes a legal claim against the company’s assets.

Down Rounds and Employee Equity

Employees often hold stock options with strike prices set at earlier, higher valuations. If a down round cuts the company’s value in half, new employees might be granted options at a lower strike price, while older employees hold expensive options that are now underwater—the current value is less than the exercise price. This gap can harm morale and retention, since employees see their potential payoff shrink.

Some companies issue new option pools to try to offset this, but new pools further dilute existing shareholders. The alternative, repricing options to lower strike prices, can trigger tax complications and often faces resistance from investors.

The Exit Question: What Down Rounds Mean for Returns

A founder who raised Series A at a $10 million valuation and sells the company for $50 million might initially expect a strong exit. If that company instead raises a Series B down round at $7 million, then Series C at $12 million, the founder’s ownership percentage may have changed enough through dilution that the final exit proceeds are much smaller, even at the higher absolute company value.

Investors who entered at the down round price often see better returns than earlier investors, because they bought in cheaper. This misalignment of incentives is one reason down rounds become contentious events in startup history. The founders who held through the down round give up equity to survive, while later investors profit from the desperation.