The investment framework of Benjamin Graham — Warren Buffett's mentor — is based almost completely on audited data.
The Value Investing framework of Benjamin Graham — Warren Buffett's mentor — is based almost completely on annual data. The Graham Number requires the average EPS of the past three years, Earnings and Dividends are checked over periods of 5-20 years, and so on.
Thus, once a stock is evaluated against Graham's framework using its annual data, it does not need to be reevaluated every quarter. A full Graham analysis is valid for a minimum of one year; and often stays valid for much longer. Drastic changes are highly unlikely in a correctly diversified Graham portfolio.
Unaudited - EPS (TTM)
Interim financial statements such as quarterly ones are also generally unaudited, and do not adhere to accounting standards such as GAAP as strictly as the annual ones do.
Therefore, analyses by GrahamValue are done almost exclusively with annual data; the only exception being the NCAV Graham Grade which requires a positive EPS (TTM).
Different companies release their Annual Results at different times of the year. So GrahamValue's database is updated every few days, reflecting the latest Annual Financial Data, EPS (TTM), prices and Splits / Bonuses for all stocks available at any given time.
Graham's investment framework is also unique in that it possibly is the only comprehensive framework in which the stock price is central to the final analysis.
So when a stock's price changes on GrahamValue, it doesn't just change the displayed price but several other values as well; including — potentially — the very Graham Grade of the stock. Essentially, every stock price change on GrahamValue requires a completely fresh analysis of the entire company's financials.
Splits / Bonuses
GrahamValue also adjusts all Graham price calculations for any Splits or Bonuses that have occurred after the given Fiscal Year.
For GrahamValue to present an accurate list of current Graham stocks, it also has to analyze the entire market; and not just a few displayed stocks. This is a time-consuming process, involving extensive financial data transfers and database updates.
Therefore, due to all the aforementioned reasons, all stocks on GrahamValue are updated cyclically about twice a week.
Long-Term By Design
Value Investing is a long-term activity by design. Graham's framework includes multiple rules for quality and diversification. These rules ensure that an investor always errs on the side of caution, and that even the occasional misstep has no significant effect on one's portfolio.
But stocks are usually valued by the general market based on their expected results, and not their current status. A stock that's undervalued is quite possibly so because of an overreaction to expected bad news ahead (see Sir John Templeton video below).
Therefore, short-term changes in a stock's grading need not be taken too seriously; as Graham explains below.
"Most businesses change in character and quality over the years, sometimes for the better, perhaps more often for the worse. The investor need not watch his companies’ performance like a hawk; but he should give it a good, hard look from time to time."
The logical flow of grading a stock is more complex than one might first think. The system tries to assign the highest possible Intrinsic Value to each stock, or to leave it at the highest possible Graham Grade.
Data Updates and Performance
The synchronized bumps in CPU and RAM usage every few days is from the Data Update, which takes about 12 hours.
The time taken for a screener query depends on multiple factors. Text/Select filters usually take longer than Numerical filters, Text sorts may take longer than Numerical sorts, and so on.
Sir John Templeton on Prices
Sir John Templeton, creator of the world's largest international investment funds — and student of Graham — explains how stock prices anticipate bad news rather than react to them.
Buffett On Graham
Buffett talks about his working and personal relationship with Graham, naming his son after Graham, and the time he offered to work for Graham for free.