The StockRanks are updated as part of our computational Batch Process. This is done during the quiet hours at night after each trading day (i.e. Tuesday to Saturday - starting at 12.30 am and usually complete by 6.30 am) using financial statements data (balance sheets, cashflow statements and income statements), historical split adjusted price information, consensus estimates data and price quotes.
You can read more about how we compile company information and the frequency of updates in the Technical Guide.
Please note that the ValueRank and MomentumRank are subject to more frequent change as they are price-dependent, whereas the QualityRank is almost entirely fundamentally driven (i.e. it changes according to the company's reported updates).
We aim to have the computational batch process finished by 7.30 am each morning, ready for the trading day. However, it will sometimes be the case that we will need to work on any issues arising within a given batch so it may be published later in the day. In the site footer, we display a "timeliness" stamp that shows the latest batch we are currently using, so it's worth checking that. To explain, if you see, say, May 3rd there, then that will mean our pages are up to date as of the fundamental and trading data that was available at the close of the May 2nd trading day. Typically, you should expect to see today's date there (except when the market is closed).