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A comment on You May Be Better Off Picking Stocks at Random, Study Finds. Parent comment

Re:You May Be Better Off Picking Stocks at Random, Study Finds by kleiba on Saturday August 17, 2019 @04:32PM (#20726154)
Couldn't you phrase a strategy as a time series of binary decisions, e.g., of the type "buy/sell stock X at current time: yes or no"?

Then the inverse would be obvious. However, it's not immediately clear to me whether the claim holds that an inverse thus defined would perform better than the original strategy.

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Re:You May Be Better Off Picking Stocks at Random, Study Finds by jakelazaroff on Saturday August 17, 2019 @04:55PM (#20726307)
Does that work for the "no"s? I didn't buy or sell any stock yesterday; with that definition of "inverse", wouldn't I have to perform all possible actions? For any time, stock and amount, the inverse of inaction would be "yes, buy/sell X shares of stock Y."
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Re:You May Be Better Off Picking Stocks at Random, Study Finds by kleiba on Saturday August 17, 2019 @06:51PM (#20726942)
It wouldn't work because you don't have an unlimited amount of money. So it's impossible to turn all "no's" into "yes" for the inverse strategy.

In addition, buying/selling is not a binary action per se for stocks because you need to specify an amount.

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Re:You May Be Better Off Picking Stocks at Random, Study Finds by squeaky-clean on Saturday August 17, 2019 @07:00PM (#20726989)
Yeah there's just way too many possible ways to consider an inverse strategy. Even with your example, if my strategy is to buy GOOG at noon on Monday... Is my inverse strategy to buy 1 of every stock that isn't GOOG at Noon on Monday? Is the inverse to short GOOG? Is it to have already owned GOOG and instead sell it at Noon on Monday?
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