What exactly changes following a stock split?

Why doesn't "Shares" (on SEC balance sheet) change?

This morning, BIS split. The share price went from 10.53 to 52.3 but the number of shares listed on google finance didn't change.

another example: TWX split in 2009, but nothing changed on their balance sheets:


So what is the name of the financial item that changes following a split? something must be changing to adjust the P/E so it doesn't change after a stock split.


here are some more examples of splits that don't seem to be reflected in annual financial data. see the first comment for links. how can i find out what other factors might have changed the number of shares? end of 2007 for AAON. stock split 3:2 but no change in number of shares

date, split ratio




in 2012, google listed AAON as having 24.6M shares but morningstar shows them having 56M then. why the discrepancy? (see 2nd comment for links)


2 Answers 2


In theory*, if a company has 1m shares at $10 and does a 10 for 1 split, then the day after it has 10m shares at $1 (assuming no market move). So both the price and the number of share change, keeping the total value of the company unchanged.

Regarding your BIS, I suspect that the new number of shares has not been reported yet because it's an ETF (the number of shares in issue changes everyday due to in/out flows).

Your TWX example is not ideal either because there was a spin off on the same day as the stock split so you need to separate the two effects.

* Some studies have documented a positive stock split effect - one of the suggested reasons is that the stock becomes more liquid after the split. But other studies have rejected that conclusion, so you can probably safely consider that on average it will not have a material effect.

  • check out new examples i added to the question. especially AAON in 2007. split 3:2 but # shares didn't budge. i'm trying to get historical #shares for a stock so i can calculate historical PE's (i have prices and earnings). is there a better way to do this? or is there more information that would help me get historical # shares?
    – stuart
    Nov 6, 2014 at 17:28
  • 2
    @stuart the number of shares has been adjusted to avoid a discontinuity in the per share ratios but they have also adjusted the prices so it is neutral. For example the actual EPS in 2007 was 1.22 for 18.8m shares which translates into 0.36 for 64m shares after adjusting retrospectively for the subsequent splits. That helps keep things comparable over the years.
    – assylias
    Nov 6, 2014 at 17:52
  • 1
    If you really want the exact number of shares back in 07 you can always download the company's annual report for that year.
    – assylias
    Nov 6, 2014 at 17:54
  • ah, that's what i didn't realize -- that morningstar was showing split-adjusted historical shares. thank you!
    – stuart
    Nov 8, 2014 at 19:50

This morning, BIS split. The share price went from 10.53 to 52.3 but the number of shares listed on google finance didn't change.

This is called a reverse split. Companies do this to avoid being delisted. See Chesapeake Energy's Hail Mary reverse split months before bankruptcy.

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