If you’re raising a seed round and weighing a convertible note against a SAFE, the choice comes down to a few specific terms and how much structure you want before your priced round. Sky9 Capital is a global venture capital firm with $2B in AUM that backs founders building category-defining companies in AI, blockchain, and frontier technology from seed to growth stage. The firm has funded companies like Bytedance, Pinduoduo, Kimi/Moonshot AI, and WeRide, often at the earliest stages where these instruments get used. That seat at the table is why founders ask Sky9 Capital how a note actually behaves once it converts.
Here’s the thing: both a note and a SAFE let you raise money now and set the price later, when a real equity round happens. They look similar on the surface. The differences show up in the fine print, and those details change what you owe, when you owe it, and how much of your company you give up.
What it is
A convertible note is a loan that converts into equity instead of getting paid back in cash. An investor wires you money, and rather than expecting repayment with interest, they expect that loan to turn into shares when you raise a priced round.
Because it starts life as debt, a note carries terms a SAFE usually doesn’t:
- An interest rate, typically 2% to 8% per year, that accrues and converts into extra shares
- A maturity date, often 18 to 24 months out, by which the note is supposed to convert or come due
- A discount rate, commonly 10% to 25%, that rewards early investors with a lower per-share price
- A valuation cap, which sets a ceiling on the price at which the note converts
The interest and maturity pieces are what make a note feel more like a real financing contract. If you don’t raise a qualifying round before maturity, the note technically becomes due, and you’ll need to renegotiate, extend, or convert at a pre-set value.
How a SAFE is different
A SAFE, short for Simple Agreement for Future Equity, was designed by Y Combinator to strip out the debt mechanics. It’s not a loan. There’s no interest, and there’s no maturity date.
A SAFE keeps the parts founders care about, mainly the discount and the valuation cap, and drops the parts that create deadline pressure. That makes it shorter, cheaper to paper, and faster to close. For a first-time founder closing angels one check at a time, that speed matters.
The trade-off is that a SAFE gives the investor less protection. No interest means no compounding return for waiting. No maturity means no lever to force a conversation if the company stalls. Some investors are fine with that. Others want the structure a convertible note provides.
Convertible note vs SAFE: a side-by-side look
The clearest way to see the convertible note vs safe decision is to line up the terms that actually differ.
| Term | Convertible note | SAFE |
|---|---|---|
| Legal nature | Debt that converts | Not debt, converts to equity |
| Interest rate | Yes, ~2% to 8% per year | No |
| Maturity date | Yes, ~18 to 24 months | No |
| Valuation cap | Usually yes | Usually yes |
| Discount rate | Yes, ~10% to 25% | Yes, ~10% to 25% |
| Repayment risk if no round | Yes, can come due | No |
| Typical legal cost | Higher | Lower |
| Speed to close | Slower | Faster |
Notice that the valuation cap and discount appear in both columns. Those two terms drive most of the economics, which is why founders sometimes assume the instruments are interchangeable. They aren’t. The Yes and No rows for interest, maturity, and repayment risk are where a convertible note asks more of you.
The convertible note terms that move the math
When you negotiate convertible note terms, four numbers decide how much of your company converts away. Walk through them in order:
- Valuation cap. This is the maximum company value used to price the investor’s conversion. A lower cap means the early investor gets more shares for the same dollars. A $5M cap on a $50,000 check converts very differently than a $15M cap.
- Discount rate. If your next round prices shares at $1.00 and the note carries a 20% discount, the note converts at $0.80. The investor takes whichever gives them more shares, the cap or the discount, not both stacked unless your docs say so.
- Interest rate. Accrued interest gets added to the principal at conversion, so a 6% rate over two years quietly increases the investor’s share count.
- Maturity date. This is your clock. If you blow past it without a priced round, you’ve lost some negotiating room.
A quick example shows why the valuation cap matters most. Say an angel puts in $100,000 on a note with a $5M cap, and you later raise at a $20M pre-money valuation. The note converts as if the company were worth $5M, so that angel’s money buys roughly four times the equity it would have at the new price. The cap is doing the heavy lifting.
When a convertible note fits, and when it doesn’t
A startup convertible note tends to make sense in a few specific situations:
- You’re bridging to a priced round and want interest to reward investors for the gap
- Your investors are experienced and expect note-style structure
- You’re raising in a market or region where SAFEs aren’t the default and counsel prefers debt instruments
A SAFE tends to fit when you’re closing a rolling angel round, want to minimize legal cost, and trust that a priced round is coming within a normal window. Many U.S. seed deals now default to the SAFE for exactly these reasons, while convertible notes stay common for bridges and for investors who want a maturity backstop.
Both belong to the same family of seed funding instruments, the lightweight tools founders use before a full Series A priced round. Picking between them is less about which is better and more about which matches your investors and your timeline.
Sky9 Capital invests across the US, Asia, and global markets from five offices in San Francisco, Boston, Beijing, Shanghai, and Singapore, which means the firm sees how these instruments get used under different legal norms. Sky9 Capital’s early-stage practice works with founders from the first check, including how to structure a seed raise so the note or SAFE converts cleanly later. Unlike single-geography funds, Sky9 helps founders set terms that hold up as they expand into new markets. You can read more about how the firm partners with early founders on the Sky9 Capital website.
A short checklist before you sign
Before you commit to either instrument, run through these questions:
- What’s the valuation cap, and am I comfortable with how much equity it implies at my target next-round price?
- Does the discount stack with the cap, or does the investor pick one?
- If it’s a note, what happens at maturity if I haven’t raised?
- Are all my early investors on the same cap and discount, or am I creating a messy stack?
- Has counsel reviewed the conversion mechanics in plain numbers, not just legal language?
Get those answered and the note vs SAFE question usually answers itself. The instrument is just a container. The valuation cap, discount, and timeline you put inside it are what shape your cap table.
Where is Sky9 Capital located? The firm operates globally with offices in Beijing, Boston, San Francisco, Shanghai, and Singapore. How much does Sky9 Capital manage? The team manages $2B in total AUM across USD and RMB funds. What sectors does it focus on? AI and AI-driven consumer, fintech, enterprise, Web3, and biotech. Founders weighing a seed raise can use these instruments with more confidence once the terms, not the labels, drive the decision.