# Stock Market math question **URL:** \ **Category:** Factual Questions\ **Created:** [April 9, 2020, 8:26pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457 "2020-04-09T20:26:14Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [April 9, 2020, 8:26pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/1 "2020-04-09T20:26:14Z")
On February 12 the DOW hit 29,951. On March 23 the DOW dropped to 18591. Today the DOW is at 23, 868. What is the percentage of the February 12 to March 23 drop and what is the percentage of the March 23 to April 9 rise? ---
**Author:** ![FastDan1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fastdan1/32/427_2.png) [@FastDan1](https://boards.straightdope.com/u/FastDan1)\ **Post date:** [April 9, 2020, 8:43pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/2 "2020-04-09T20:43:59Z")
Drop was 11,360 points. 11,360/29,951 is approx 38% drop. Rise was 5,277 points. 5,277/18,591 is approx 28% rise. ---
**Author:** ![dougrb](https://avatars.discourse-cdn.com/v4/letter/d/76d3ee/32.png) [@dougrb](https://boards.straightdope.com/u/dougrb)\ **Post date:** [April 9, 2020, 8:46pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/3 "2020-04-09T20:46:35Z")
38% drop followed by 28% rise. Ninja’d ---
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [April 9, 2020, 8:47pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/4 "2020-04-09T20:47:55Z")
Even if the rise from March 23rd had been 38%, you wouldn’t be back to your original index value, because you variance is based off a lower denominator. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [April 9, 2020, 8:51pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/5 "2020-04-09T20:51:40Z")
> [@dougrb](#): > > 38% drop followed by 28% rise. > > Ninja’d He’s not named FastDan1 for nothin’! ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [April 9, 2020, 8:56pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/6 "2020-04-09T20:56:05Z")
> [@Omar\_Little](#): > > Even if the rise from March 23rd had been 38%, you wouldn’t be back to your original index value, because you variance is based off a lower denominator. So a rise up from the low of 18591 back to the peak of 29951 would be what percentage? ---
**Author:** ![FastDan1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fastdan1/32/427_2.png) [@FastDan1](https://boards.straightdope.com/u/FastDan1)\ **Post date:** [April 9, 2020, 8:57pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/7 "2020-04-09T20:57:44Z")
61% - 11,360/18,591 ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [April 10, 2020, 5:17pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/8 "2020-04-10T17:17:59Z")
It should be noted that a 38% drop followed by a 38% rise (or vis versa) won’t actually get you back where you started because (1+0.38)\*(1-0.38) = 0.856 =/= 1 This is because the 38% drop started from larger baseline than the 38% increase. This is why if I ruled the world all references to stock market indices would be log transformed. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [April 10, 2020, 6:06pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/9 "2020-04-10T18:06:29Z")
> [@Buck\_Godot](#): > > This is why if I ruled the world all references to stock market indices would be log transformed. You might still have trouble because some stock market indices are weighted and some are not. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [April 10, 2020, 8:20pm UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/10 "2020-04-10T20:20:26Z")
This is kinda elementary math, so could you maybe tell us what exactly you’re trying to figure out and why? Might help get a better explanation. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [April 11, 2020, 1:02am UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/11 "2020-04-11T01:02:29Z")
Just a phone conversation with a friend about his getting back into the Market “at the bottom”. I did some math and came up with the same figures: 38% / 26%, but he disputed them (without, of course, coming up with his own). I just wanted to make sure my math was correct. ---
**Author:** ![RioRico](https://avatars.discourse-cdn.com/v4/letter/r/f04885/32.png) [@RioRico](https://boards.straightdope.com/u/RioRico)\ **Post date:** [April 11, 2020, 2:10am UTC](https://boards.straightdope.com/t/stock-market-math-question/851457/12 "2020-04-11T02:10:34Z")
> [@Mangosteen](#): > > On February 12 the DOW hit 29,951. On March 23 the DOW dropped to 18591. Today the DOW is at 23, 868. Questions for anyone: How much of the rise to the Feb 12 high was debt-powered stock buybacks? Where did the money for the current bounce-back come from? Where did the “lost” money go?