Before tracking funds, get the rules straight. This time, we're talking about transaction finality.
Ethereum's proof-of-stake system uses the Casper FFG mechanism. Each epoch contains 32 slots and lasts about 6.4 minutes.
When receiving a large payment, wait for enough confirmations or for finalization before shipping. Don't just look at whether it's “on-chain.”
On Ethereum, the $ETH staked is the guarantee of finality: rewriting a finalized block would mean losing a large amount of stake. Current price: 2241.92.