If you want a current indicator you have to pay for it from companies like Markit that poll hedge funds. The idea being that if you want to know the number you pay by including your own data that they can then show to other funds in aggregate.
For the borrow rate you ask your prime brokerage(like a bank but for holding equities/derivatives/etc). They'll go find you shares and figure out what rate to charge you, while adding their own rate on top.
1) Total Shares of 273Million this is what finviz is using. This includes locked up shares that can't trade right now
2) the Currently tradable float, this is 32 Million and what I, Bloomberg, Markit, and any non budget site will use as these are the only shares that currently matter.
LifeOfPi mentioned the short float to = 7%. Chollida1 mentioned the 7% figure was using 273mil shares as a base.
So wouldn't the total shorted shares equal 19mil? (19mil = 273mil X 7%). However, Chollidal mentioned in the first post that 27mil shares are shorted. Trying to figure out how to bridge the gap between 19mil and 27mil...
PS. Not trying to nit-pick. The comments are very useful. Maybe I'm missing something....
In regards to borrow rates, there are some sources that are fairly accurate, but usually only to prime brokers themselves. There is no public exchange.
Interactive Brokers is the only retail broker that I know of that is fairly transparent and fair in terms of borrow rates.
As pointed out above, if there is then a subsequent increase in price, and this can be because short sellers are forced to buy back their short for any reason (short squeeze), prices can very quickly increase out of control. The best case of this was the Porsche-Volkswagon "infinity squeeze" - when mathematically speaking, absent intervention, the price would have gone to infinity.
https://moxreports.com/vw-infinity-squeeze/
Good times.