Valar Atomics vs Day One. When a pro rata fight between founder and investor goes nuclear.
For those who don't live their every hour on X (bless you!) I'll summarize. Stick with me, because this stuff is fascinating:
@ValarAtomics is a startup that builds nuclear reactors and just announced a $1B Series B from
@Sequoia in August 2026.
On October 9 it sued
@DayOneVC, its seed investor and Series A co-lead, in the Delaware Court of Chancery. The issue in question comes from the removal of a "spring back" provision.
Pro rata is the right of an investor to maintain their prior level of ownership by buying additional shares at the current round's financing. It's a common right granted to Major investors.
If major investors waive their pro rata and the company lets one of them back in anyway, Spring Back means everyone gets their rights back at the same proportion.
Well, the day before Valar's $1B Series B closed, Valar and a majority of Major Investors share class amended the agreement to take that spring back clause out. Meaning the company can now include or exclude any investor they want.
Day One's GP
@mashadrokova says amending in this fashion singled them out as an investor which goes against the letter of their agreement and against their rights as a Major Investor.
The question at hand is: Can founders get a majority of investors to change the investor rights agreement to deny the rights of a particular investor? And most importantly, is that what happened here?
My friend
@Yashreeka, Partner at
@AshurstPerkins, joined me to unpack what the clause actually means, whether the removal was done the right way, and what happens in reality when founders and investors disagree over pro rata.
Must listen because this is the legal stuff Claude can't teach you. Full episode below 👇👇👇