The Cap Trap
aaronkharris.com
aaronkharris.com
The median pre-money Series A valuation for all WSGR startups is ~$8.0m [1], which is likely on the higher end.
Also, uncapped notes do not get diluted when raising your Series A, which is additional dilution for the entrepreneur.
For example, let's say you raise $5m uncapped notes with no discount. If you then raise a $3m Series A at a $8m pre-money valuation, you'll end up giving away more than 50% of your company, not counting interest or option pool. At a $15m pre-money valuation, you'll be giving away over 40% of your company.
Entrepreneurs should be equally careful with SAFEs.
[1] http://www.wsgr.com/publications/PDFSearch/EntrepreneursRepo...
I don't think the numbers given in your example are particularly realistic. Series A rounds are almost never smaller than seed rounds and are usually at least 3x - 10x.
If you raise $2m or $3m on uncapped, no-discount notes, you basically need to turn that into a $10m+ pre-money company upon raising your Series A. If you raise $4m or 5m+ seed, it gets even harder. And this is assuming no cap or discount, which is unlikely.
You are correct that Series A rounds are usually not smaller, in which case if you raise several million seed on uncapped notes and cannot leverage that into a much more valuable company, you'll be unable to raise a Series A.
This is all manageable by the entrepreneur, but it's important to make sure you understand what's happening and where the risks are. It seems a lot of entrepreneurs don't.
There is no "rule" about implied valuation either. Entrepreneurs can raise $3m in notes $100k at a time, usually from investors that are much less price-sensitive than VCs leading a priced round. It's a lot harder to raise a priced Series A at a $10m+ valuation than raising piecemeal notes at the same valuation cap (or uncapped notes, even).
Again, this is all manageable by the entrepreneur, but there are no "rules" like it often appears from the outside.
This isn't necessarily true. If I recall correctly, the default language in Clerky's notes or the YC Safe provides mechanisms for getting around this, either by (a) issuing a different class of stock to noteholders with a different liquidation preference (e.g. Series A vs. A-1 shares) or (b) issuing the extra shares resulting from a discount or cap in common rather than preferred.
As for the SAFE, you're right that it has protections on the liquidation preference - one more reason that it's superior to a convertible note.