Bridge funding is short-term capital that covers a company’s immediate cash needs until a larger, permanent financing event closes. Rounds typically last six months to three years and carry higher costs than conventional financing because the lender or investor is pricing in urgency and risk. Repayment is tied to a specific future event: a priced equity round, an acquisition, an asset sale, or a refinance. When that event happens, the bridge either gets paid back in cash or converts into equity in the company.
Why Companies Reach for a Bridge
The usual trigger is a timing mismatch. Cash is running low, but the next major funding round is still months from closing. Due diligence, legal negotiation, and investor committee approvals almost always take longer than founders plan for, and bridge capital keeps the company operating during that gap.
The textbook startup scenario: seed capital is nearly exhausted, but the company needs another three to six months to hit the revenue milestones its Series A investors want to see. A bridge covers payroll, rent, and operations until those milestones land. Another common use is funding a time-sensitive acquisition that can’t wait for a full equity or debt raise to close. Bridge capital also appears during IPO preparation and corporate acquisitions, where regulatory filings and audits stretch the timeline and running out of cash mid-process would force the company to accept a lower valuation just to close faster.
How Bridge Funding Is Structured
Three structures cover almost every bridge round: traditional bridge loans, convertible notes, and SAFEs. All three serve the same interim purpose. Their mechanics diverge in ways that matter for both sides.
Bridge Loans
A bridge loan is straightforward debt: a set interest rate, a maturity date, and an obligation to repay in cash. This form is most common with established companies and real estate deals where there’s clear collateral or predictable revenue. Interest rates typically run between 6% and 10%, higher for riskier deals. Origination fees usually fall between 0.5% and 2% of the loan amount, on top of standard closing costs.
The lender expects repayment from the proceeds of whatever event the loan is bridging toward: a property sale, a refinance, an equity round, or an acquisition closing. Terms generally run six months to three years. Because the timeline is short and the risk is concentrated, lenders often require collateral and may demand personal guarantees from the borrower.
Convertible Notes
Convertible notes dominate the startup world. A convertible note is technically a loan, but instead of being repaid in cash, it converts into equity when the company raises its next qualifying round. The principal plus accrued interest is exchanged for shares at a price determined by the note’s terms.
Interest rates on convertible notes typically range from 2% to 8%, lower than bridge loans because the real return comes from the equity conversion. Maturity dates usually fall between 18 and 24 months. The key advantage for founders is that convertible notes postpone the valuation argument. Everyone agrees to let the next round’s lead investor set the price, and the bridge investor gets a discount for taking earlier risk.
SAFEs
The SAFE, or Simple Agreement for Future Equity, was created by Y Combinator and has become a standard early-stage bridge instrument. Like a convertible note, an investor’s money converts into equity at a future priced round. Unlike a note, a SAFE is not debt. It has no interest rate and no maturity date, so no clock is ticking toward a forced conversion or repayment.1Y Combinator. YC Safe Financing Documents The tradeoff: SAFE holders have no repayment right if things go sideways. They’re betting entirely on the company eventually raising a priced round or being acquired.
Most SAFEs today use a post-money structure, meaning the investor’s ownership percentage is calculated after all SAFE money is accounted for but before new money from the priced round comes in.1Y Combinator. YC Safe Financing Documents This gives both sides more clarity about dilution upfront. Founders who stack multiple SAFEs at different caps can still be surprised when everything converts at once.
The Terms That Decide the Deal
A handful of terms control how much equity the bridge investor ends up with and how much dilution the founders absorb. They apply across all three structures with small variations.
Valuation Caps and Discounts
Both compensate the bridge investor for taking risk before the company’s value is proven. They can appear alone or together, and when both are present, the investor typically gets whichever produces the better outcome.
A valuation cap sets a maximum company valuation for the purpose of the investor’s conversion, regardless of what the next round actually prices at. If a note has a $5 million cap and the Series A prices the company at $10 million, the bridge investor’s effective share price is cut in half, giving them roughly twice as many shares per dollar as the Series A investors get.
A conversion discount is simpler: the bridge investor pays a reduced price per share compared to what the new investors pay. Discounts typically run 15% to 25%. When a note carries both a cap and a discount, the cap usually produces the bigger benefit in a successful company, because a high Series A valuation makes the cap’s ceiling more valuable than a percentage discount.
Maturity Dates
For bridge loans and convertible notes, the maturity date is when the money is legally due. If the anticipated round hasn’t closed by then, the note holder can generally demand cash repayment, convert at a pre-set valuation (often unfavorable to the company), or negotiate an extension with revised terms.
This is where bridge financing gets genuinely dangerous. If the company can’t repay and the investor won’t extend, the investor may have the right to force a liquidation or convert at a valuation so low it wipes out a significant chunk of founder equity. Most situations get resolved through negotiation rather than litigation, but leverage shifts entirely to the investor once maturity hits without an exit event. SAFEs sidestep this problem by having no maturity date at all, which is a major reason founders prefer them.
Conversion Triggers
Conversion triggers are the contractual events that switch a note or SAFE from its current form into equity. The primary trigger is a qualified financing: a subsequent equity round meeting a minimum size threshold defined in the agreement. Once that round closes, the bridge instrument converts into the same class of preferred stock the new investors receive, at the lower price created by the cap or discount.
Other triggers include acquisition or merger (where the investor receives cash or acquirer stock) and, for convertible notes, reaching maturity without a qualified round. The mechanics for each trigger should be spelled out in the agreement, because outcomes can vary dramatically depending on which one fires.
Where the Money Comes From
The source of bridge capital usually depends on the company’s stage and what the money is for. Motivations differ, which shapes the terms each source will accept.
- Existing investors. Venture capital firms and angels who already have equity in the company are the most common bridge providers for startups. Their motivation is straightforward: protect their existing investment by keeping the company alive until the next milestone. They’ll often accept more founder-friendly terms because a failed company is worth zero to them regardless.
- Commercial banks and specialty lenders. These institutions provide traditional secured bridge loans, particularly for real estate and acquisition financing. They require collateral, focus on cash repayment rather than equity upside, and charge market interest rates.
- Mezzanine funds and specialized bridge lenders. These providers work in riskier territory, offering capital for larger or more complex deals. They charge higher interest rates and frequently negotiate for equity kickers like warrants, which give them the right to purchase shares at a set price.
When existing investors provide the bridge, the process moves quickly because they already know the company. New investors and institutional lenders bring additional due diligence and more aggressive terms.
What Can Go Wrong
Bridge financing solves an immediate problem and creates new ones if the anticipated exit event doesn’t happen on schedule.
Cumulative Dilution
Every bridge instrument that converts into equity dilutes existing shareholders. Caps and discounts mean bridge investors get more shares per dollar than the next round’s investors. Founders who raise multiple bridge rounds at low valuation caps can arrive at their Series A only to find they own far less of the company than they expected. Each individual note might look manageable in isolation. Several converting simultaneously is a different picture.
Personal Guarantees
Secured bridge loans, especially in real estate and small business contexts, frequently require personal guarantees from the borrower. If the loan defaults, the lender can pursue the borrower’s personal assets, not just the business collateral. Wage garnishment and asset seizure are both on the table when a personally guaranteed bridge loan goes bad. Understand that a personal guarantee puts your own finances on the line, not just the company’s.
The Maturity Date Trap
A convertible note’s maturity date creates a hard deadline that gives the investor leverage if the next round hasn’t closed in time. At maturity, the investor can demand cash the company almost certainly doesn’t have, or force conversion at terms that heavily favor the investor. Even if the investor agrees to extend, they’ll typically extract better terms: a lower valuation cap, a higher discount, or additional warrants. Each extension weakens the founder’s position going into the eventual priced round.
A Note on SEC Filings
Most startup bridge rounds are structured as private placements under Regulation D. Exempt from full SEC registration does not mean unregulated. A company selling securities under Rule 506 of Regulation D must file a Form D notice with the SEC within 15 calendar days after the first sale, measured from when the first investor becomes irrevocably committed to invest, not when the money arrives. The SEC charges no fee for Form D filings.2U.S. Securities and Exchange Commission. Filing a Form D Notice Many states have their own notice filing requirements that piggyback on the federal Form D, with their own deadlines and fees.3eCFR. 17 CFR Part 230 – Regulation D Rules Governing the Limited Offer and Sale of Securities Without Registration Under the Securities Act of 1933 Missing the deadline doesn’t automatically kill the exemption, but it complicates things with state regulators and raises red flags in future due diligence.