I'm new to stocks, so let's get that out of the way. But I was curious, how quickly, does the short float ratio change on websites like cnn, nasdaq.com, finviz, google, etc.? Also, if it does change on a short time scale, does it adjust, do you know of anywhere that is real time in the pre-market?
The short float ratio and percent change are all calculated based on the short interest (the total number of shares shorted). The short interest data for Nasdaq and NYSE stocks is published every two weeks.
NasdaqTrader.com shows the exact dates for when short interest is published for Nasdaq stocks, and also says the following:
FINRA member firms are required to report their short positions as of settlement on (1) the 15th of each month, or the preceding business day if the 15th is not a business day, and (2) as of settlement on the last business day of the month.* The reports must be filed by the second business day after the reporting settlement date. FINRA compiles the short interest data and provides it for publication on the 8th business day after the reporting settlement date.
The NYSE also shows the exact dates for when short interest is published for NYSE stocks, and those dates are exactly the same as for Nasdaq stocks.
Since the short interest is only updated once every 2 weeks, there is no way to see real-time updating of the short float and percent change. That information only gets updated once every 2 weeks - after each publication of the short interest.