The funny thing is, it's not really bilking the stock market. The whole argument for stock trading is that traders create value by accurately pricing securities, and thus allocating capital efficiently. Time travel is just a ridiculously efficient means of doing so. Given common access to Time-Turners, the stock market would literally be perfectly efficient(assuming that using turner-induced stock prices doesn't violate the 6-hour rule). People without them would be very pissed off, but I'd actually argue it as being the right and proper way to run a stock market if the technology existed.
The only thing is, once you have enough time turners to control most of the volume of the market, there are no longer any linear-time causal inputs (read: people) deciding what directions the market will take. Market fluctuations would literally come from nowhere, though it might be best said that they would come from Time. And given Harry's previous scary experiment (DO NOT MESS WITH TIME, ch. 17), I'm not sure it's such a good idea to let Time be the one to control this.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 81, which should be published later today. The previous thread passed 400 comments as of the time of this writing, so it will pass 500 comments soon after the next chapter is posted, if not before. I suggest refraining from commenting here until chapter 81 is posted; comment in the 12th thread until you read chapter 81. After chapter 81 is posted, I suggest all discussion of previous guesses be kept here, with links to comments in the previous thread.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.) When posted, chapter 81 should appear here.
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six, seven, eight,nine, ten, eleven, twelve.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: