As per https://www.ycombinator.com/deal “The $125k safe and the MFN safe will each convert into preferred shares when your company raises money by selling preferred shares in a priced equity round, which we refer to below as the “Safe Conversion Financing” (this will typically be your “Series A” or “Series Seed” financing, whichever happens first).”
Edit: Sorry, I am absolutely wrong here. I completely misunderstood what nirmel was saying.
They are correct. The MFN safe converts at the best terms. So if there is a SAFE with a post-money $3.75m cap, then even if the next round is priced at $100m, YC gets 10% at that 100m valuation. It converts at an equivalent ownership compared to the cap. That's why caps exist.
The MFN applies to other SAFEs too. YC will get the "best" price during the priced conversion. If you took other money at a lower SAFE, that would peg the "best" price in the conversion -- and thus, that's what YC's $375k would get.
Thank you for the correction. They mention this at the footnote of the article: “1 The $375,000 is on an uncapped safe with ‘Most Favored Nation’ (MFN) terms. MFN means that this safe will take on the terms of the lowest cap safe (or other most favorable terms) that is issued between the start of the batch and the next equity round. Simply put, we’re giving the company money now but at terms you’ll negotiate with future investors.”
As per https://www.ycombinator.com/deal “The $125k safe and the MFN safe will each convert into preferred shares when your company raises money by selling preferred shares in a priced equity round, which we refer to below as the “Safe Conversion Financing” (this will typically be your “Series A” or “Series Seed” financing, whichever happens first).”
Edit: Sorry, I am absolutely wrong here. I completely misunderstood what nirmel was saying.