Proof of stake secures a chain by making validators lock value (stake) that is slashed if they attest invalidly. It replaced proof of work's energy auction with a capital auction: security is backed by the value at risk rather than the compute expended.
The tradeoffs are argued (stake concentration, weak-subjectivity checkpoints) but for payments the relevant facts are practical: fast finality and fees low enough for commerce.
Proof of stake secures a chain by capital at risk rather than energy expended: validators lock value, stake, and attest blocks, with dishonest attestation punished by slashing the stake. Lying becomes economically self-defeating, which converts the security budget from burned electricity to bonded capital earning return for honest service.
The mechanics matter less to a payments user than the derived properties. Finality: modern stake chains commit blocks irreversibly in explicit steps, so settlement lands in seconds rather than stacking probabilistic confirmations. Throughput and cost: consensus at the scale stake designs reach keeps fees at levels commerce can carry, which is why the chains settling most payment volume are stake-based.
The critique that follows it around, concentration of stake, is real at the margins and bounded by the economics: large stakers still profit more from honest operation than from attacks that destroy the value of their own stake. For anyone using the chain as a settlement rail rather than governing it, the security question reduces to whether attacking it costs more than it gains, and stake designs keep that arithmetic pointed the right way.
The networks U.CASH settles across, Ethereum and its L2s, Solana, Polygon, Tron, all run stake variants, which is why their payment-shaped properties are fast finality at cent-level fees rather than block rewards and mining economics.
The networks U.CASH settles on (Ethereum and its L2s, Solana, Polygon, Tron) all run proof-of-stake variants, which is why settlement runs to seconds and fees to cents.
Merchants do not hold stake; they ride the guarantees it pays for: seconds-level finality, fees that do not eat small tickets, and chains whose security budget does not depend on energy politics. Those properties are why checkout assets live where they live. On evaluation: when comparing settlement chains for a corridor, the consensus family matters less than the delivered properties, finality time, fee at your ticket size, and the native availability of your settlement assets. Those three numbers, checkable per chain, decide more than any ideology about how the blocks get agreed.
Every term behind the rails, the assets, and the settlement.