Formally I'm an undergraduate. Not in a hurry to graduate -- I take courses when they are interesting to me / relevant to my research / I happen to have the bandwidth.
I am already several years into my career and I have a spouse to support, so I'm ambivalent about formally attending graduate school -- at least anytime soon -- since that would introduce lots of time pressure and administrivia for little apparent benefit. My relationship with my supervisor is mostly informal
I own it and have tried to read it but man I have a really hard time getting past the first chapter. I think it would be better for me to study Prolog first for a while before trying to continue reading this. I've always heard good things about it.
As to your second question: Yes, Bill Joy did that in 1976 when he added a visual mode to his line editor ex that was itself based on ed. The mode was called vi (for "visual") and updated the screen as you typed ex commands preceded by a colon. All vi descendants have this feature, including Vim. :-)
I think it was in ed already. The POSIX ed spec says: "Any character other than <space> or <newline> can be used instead of a slash to delimit the RE and the replacement."
The Yoneda Lemma is really some kind of "fundamental theorem" of elementary category theory. Then there are Freyd's Adjoint Functor Theorem, Kan extensions and probably others I'm forgetting...
> We already know that a significant majority of the loans in CLOs have weak covenants that offer investors only minimal legal protection; in industry parlance, they are “cov lite.” The holders of leveraged loans will thus be fortunate to get pennies on the dollar as companies default—nothing close to the 70 cents that has been standard in the past.
The "haircut" on risky assets stops you leveraging it too much. I think it's about 5% for US treasury bonds. So for every 100 I want to finance I need to have 5 cash on hand. Itsuch higher for riskier assets and that keeps leverage down. Also when things start to get edgy banks demand a bigger haircut further reducing the available leverage forcing you to delever (e.g. March)
If you step through the arithmetic, you see that a 5% haircut can take you to 20x leverage. It's a geometric series.
That means that investors' internal risk limits are the binding constraint, not repo haircuts.
It's another way of saying that the financial sector sets its own leverage. Historically, that has not turned out well. It's why Dodd-Frank included a leverage rule for large banks.
> That means that investors' internal risk limits are the binding constraint, not repo haircuts.
While part of risk, expected return is a larger binding constraint in most cases over risk limits. I'm probably not going to lever up 20x for an tiny expected return. On the other hand, I may very well lever up 5-10x on something 50x more risky than treasuries if the 10yr is yielding 0.725%.
In practice most PM's have a VaR limit and a battery of dollar exposure limits, which are all set by the risk department.
There is some credible research which suggests that large financial institutions act as if they are optimizing mean return subject to a VaR constraint [1].
VaR is a fake number for way too many reasons to get into and anyone who paid attention to VaR these past few months would have lost a ridiculous amount of money. I only have experience working for hedge funds and how risk is managed greatly differs from fund/strategy/assets traded. Banks no doubt manage to VaR but banks also supposedly don't have prop trading desks anymore so they function much differently now.
The discussion seems to have shifted to argument for argument's sake.
But for the sake of argument: large bank VaR models affect hedge funds because hedge funds get their leverage through their prime brokers which are... large investment banks.
Aha. Is this how folks actually attain worthwhile rates of return on very low-return, low-risk investments?
[EDIT] well no that can't be it because it requires even more money coming in for those loans, which can't provide more expected return than the bonds they're buying or the whole thing would be pointless.
Interestingly, from the point of view of category theory, an isomorphism in a category is just a morphism with a two-sided inverse. A bijection is then just an isomorphism in the category of sets.
Can you expand on that? My impression is that Kahneman and Tversky "proved" that human cognition is not Bayesian and now much of cognitive psychology is turning around and saying, no, they didn't, and it is. As a layperson, I don't know whom to believe.
Peter Flach's "Simply Logical: Intelligent Reasoning by Example" also deserves to be mentioned as a wonderful introduction to Prolog and computational logic in general. It's available as a PDF from the author (http://people.cs.bris.ac.uk/~flach/SimplyLogical.html) and also in an interactive version where the examples can be run in-browser, using SWISH: https://book.simply-logical.space/
