Superminority
The superminority is the smallest group of the largest validators that together hold a third of all stake on Solana. It matters because a third of the stake is enough to halt the network: if those validators all went offline at once, or acted together, the chain could stop confirming blocks.
Why it matters to you
Staking with a validator in this group adds your SOL to the part of the network that is already the most concentrated. Your coins aren't at risk because of it. The cost is shared by everyone: the fewer validators it takes to stop Solana, the easier it is for one shared problem to stall it.
Choosing a reliable validator outside the group does the opposite: your stake helps keep voting power spread across more operators.
Size isn't the whole story, though. Very small and brand-new validators have less of a track record, which is a risk of its own. Look for one that is neither among the largest nor brand new.
Where you see it on this site
We mark a validator Very large when it holds more than 4,000,000 SOL. That's our own rule of thumb, not an exact count of the superminority, which changes as stake moves between validators. You'll see it as a yellow Very large flag in the validator list, and stake size counts for 10 of the 100 points in our Score.
Questions
Not for your SOL. Choosing one doesn't put your coins at risk, and you still earn rewards. The downside is for the network: your stake adds to the few validators that could already halt Solana together. If two validators look equally good, picking the one outside the superminority helps keep the network spread out.