The growth in share price (and therefore overall growth of the stock in question) is different between the rows in your table.
In these scenarios though one is rising 200%: $100 to $300. And one is rising 100%: $100 to $200 and then 50%: $200 to $300.
Both of these give different results though.
Universe 1: x = 100. y = x + 100% which is 200. Then z = y + 100% which is 400.
Universe 2: x = 100. z = x + 200% which is 300.
Well that was @Joey_Fantana story at the time. 
It never was same stock in my head, nor was it same universe.
I am puzzled of aftermath discussions. I think we clarified the mystery.
I think what confuses people here is that they see the value 100% + 100% and assume that = 200%, when really it’s a case of 100% + 50% (of the new value) = 200% of the original value
Anyway @Joey_Fantana are you buying BABA on dip? 
Wasn’t this for Nio?
Oh you know it!
That way when it reverses I can sell it at 100% and buy back… oh wait how did it go…? 
The stock was irrelevant. I used NIO as it’s my only multi-bagger.
I have sometimes asked people, “do you prefer a loss of 10% followed by a gain of 50%, or would you prefer to take the gain of 50‰ first and then the 10% loss?”
Readers of this post might enjoy this from an article in the FT today about financial literacy. Are you surprised that Germans answer best, but still poorly?
Why financial literacy matters more than ever - https://on.ft.com/2IUVdzS via @FT
I will be spending 4 days in December interviewing applicants to read mathematics at Cambridge. Might there be an interview question I can invent from the above discussion?
Here is a nice story. A statistician friend who taught at Wharton Business School was discussing oil exploration with a driller in Texas. The driller said
“We will drill 5 tests holes, but then if we haven’t found oil we always give up, even though we are almost sure to find oil on the 6th drilling.”
“Why, almost sure of the 6th?”, asked statistician.
“It’s like tossing a coin. If you have 5 heads in a row the 6th must almost surely be a tail.”
“Hmm, I am not so sure. But if this is true why not drill again?”
“Well each test hole costs $100k and this sort of well usually produces $500k of oil so by the time we have drilled 5 times there is no profit to be made.”
“Hmm.”
$100 dollars with a loss of 10% is $90 and with a gain of 50% ($45) = $135
$100 dollars with a gain of 50% is $150 dollars and with a loss of 10% ($15) = $135
I think that makes me financially illiterate. Am I missing something here? Should these be different answers?
You are correct of course.
1.5 x 0.9 = 0.9 x 1.5
I wonder if someone at the FT transcribed something wrong. I would have expected the choices in question 1 to be
• More than $110
• Exactly $110
• Less than $110
• Do not know
I thought it was a trick question. Great, my parchment from the Dept. of Mathematics doesn’t need to be torn up.
Yeah i noticed that myself.
It’s… do the same calculations using the price x holdings and the result will be 100% identical.
Agreed, they either see 100% + 100% as 300%; or they see 100% + 100% as 200% instead of 100%+50%(of the new value) respectively.
Its discussion like this that makes me glad I gave up mathematics after primary school. 
Yes exactly this.
Story 1: 
grows 200% =
Story 2: grows 100% = , sold , bought , grows 100% =
So story two is 100% then 100%. The confusion is that does not equal the 200% in story 1. That’s actually 300% so will take longer to get.
I think the big problem is as I mentioned above, people think 100% + 100% as 300%; or they see 100% + 100% as 200% instead of 100%+50%(of the new value) respectively.
The key takehome message from my original point waaaay back in this thread was that the % increase or decrease you’re seeing on your screen is related to a linear growth of the initial starting amount, and does not compound in the way that 1 apple becomes 2, becomes 4, becomes 8. If that was the case, it begs the question, what is the the compounding period, daily? monthly? And if we kept compounding our gains we’d all be minted.
e.g. One day we get 10% on our $100 dollars giving us $110. The next day if we see our account is up another 10%, we now have $120 dollars or a rise of 20% overall, not $121 and a rise of 21% which would be the case if we were compounding.
Yeah that’s my key takeaway. There is no compounding on a non-dividend stock if you buy and hold. As there is no period end. The only way compounding applies here is if you regularly invest, and even then that’s not really compounding; it’s contributing.
For compounding to work on these stocks, as I said earlier, you need to;
A) switch stocks, and
B) have the 2nd stock grow at a faster rate than the original
Spot on. And now lets banish this thread forever.