willdearden

3 years agodiscuss

People have different risk exposures and different risk appetites. If you're a corn farmer then your entire livelihood is tied to the price of corn. You're willing to give up expected value to reduce risk by selling futures and there are others who are less exposed to corn prices who are willing to take the other side of that trade.

willdearden

3 years agodiscuss

FWIW for my comment I essentially used your code and cleaned up compiler-generated imperative code.

So yes it used the fact that it only recursed to n-1 but did not use any optimizations related to booleans. And looking at other examples can see general principles. You store a data structure for each function which acts as a cache. For example, suppose you said even(0) = True, even(1) = False, and even(n) = even(n - 2), then one way would to unroll it would be to use a size 2 ring buffer as a cache.

willdearden

3 years agodiscuss

Here's how I would write the loop version of this. It does involve an optimization since we know parity only depends on n - 1.

  #include <algorithm>
  
  template <typename T>
  bool even(T n)
  {
      bool is_even{true}, is_odd{false};
      for (; n--;)
      {
          std::swap(is_even, is_odd);
      }
      return is_even;
  }

willdearden

4 years agodiscuss

I was there until the end. It was definitely fading into obscurity but still had >50% of peak numbers. And we were switching to C++ in the last year or so.

willdearden

4 years agodiscuss

There is actually already a Scheme interpreter implemented in Rust (https://github.com/mattwparas/steel) which has the same name for the exact reasons you stated.

willdearden

4 years agodiscuss

Veterans Affairs? Virginia?

willdearden

4 years agodiscuss

There is a professor who was at Wisconsin, Charles Manski, who developed partial identification, which uses tons of these decompositions.

Idea is let's say you have a binary survey question where 80% respond and 90% of them respond "yes". What can we say about population "yes" rate (assume sample size is huge for simplicity)?

P(Yes) = P(Yes | response) * P(response) + P(Yes | no response) * P(no response) = 0.9 * 0.8 + P(Yes | no response) * 0.2 = 0.72 + P(Yes | no response) * 0.2

Then 0 <= P(Yes | no response) <= 1, so 0.72 <= P(Yes) <= 0.92. This example is somewhat trivial but it's a useful technique for showing exactly how your assumptions map to inferences.

willdearden

4 years agodiscuss

https://www.sec.gov/news/press-release/2021-155

You absolutely can get charged for trading in a similar company.

willdearden

5 years agodiscuss

Reminds me of the Kairos retreats popular in Catholic high schools. I went to one and it was pretty intense and not in a forced way. Basically 4 day group therapy.

willdearden

5 years agodiscuss

Ah cool, are the internalized orders reported publicly anywhere or are they just sent to the SEC/FINRA?

willdearden

5 years agodiscuss

Most trades through a brokerage don't make it on an exchange. They're internalized by a wholesaler like Citadel Securities. Which is the reason for the question.

willdearden

5 years agodiscuss

https://www.uptake.com/blog/good-data-scientist-bad-data-sci...

done here too

willdearden

5 years agodiscuss

Probably comes from the first and second theorems of welfare economics:

https://en.wikipedia.org/wiki/Fundamental_theorems_of_welfar...

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