Hong Kong Exchanges Bids $39B to Take over London Stock Exchange

Re:Hong Kong Exchanges Bids $39B to Take over London Stock E... by dragonwriter on Wednesday September 11, 2019 @12:33PM (#20941997)

The expected long-term effects of each anticipated Brexit scenario weighted by the current perception of the likelihood of each should be, sure.

OTOH, as there is considerable and evolving uncertainty about even the short-term Brexit prospects (as in, will the UK leave, and if so when and on what terms), estimates of the likelihood of various long-term scenarios are likely to also be in considerable flux,even before considering potential evolution in estimates of the effects of each potential scenario.

“The market knows the future and has already completely priced it in” is disproved every time the market moves, but people still like to treat it as some kind of deep wisdom.

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Re:Hong Kong Exchanges Bids $39B to Take over London Stock E... by klipt on Wednesday September 11, 2019 @12:39PM (#20942063)

> “The market knows the future and has already completely priced it in” is disproved every time the market moves

Well at best you can know the future probabilistically. The fair price of flipping a coin and getting $2 on heads is $1, but once the coin is flipped, you have new information, and the fair price is either $2 (if it landed heads) or $0 (if tails).

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Re:Hong Kong Exchanges Bids $39B to Take over London Stock E... by SolarNet on Wednesday September 11, 2019 @01:01PM (#20942285)

I mean more counter examples are great but any one aware of NP=/=P should be able to call bullshit on market's predictive ability.

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Re:Hong Kong Exchanges Bids $39B to Take over London Stock E... by wahern on Wednesday September 11, 2019 @01:18PM (#20942488)

FWIW, someone took the time to formally state the case: "Markets are efficient if and only if P = NP", https://arxiv.org/abs/1002.2284

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Re:Hong Kong Exchanges Bids $39B to Take over London Stock E... by dragonwriter on Wednesday September 11, 2019 @05:19PM (#20944830)

> any one aware of NP=/=P

Wait, someone finally proved P ≠ NP?

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Re:Hong Kong Exchanges Bids $39B to Take over London Stock E... by SolarNet on Wednesday September 11, 2019 @06:14PM (#20945359)

No, but it's generally understood to be very unlikely [0]. And if something as well studied as markets exhibited NP in P behavior we would have exploited it by now (FWIW, markets appear to be an efficient approximation algorithm like evolution is; approximation algorithms (like evolution) being something we use all the time to solve engineering problems).

[0] https://www.scottaaronson.com/papers/npcomplete.pdf

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