throwaway283719 · HackerTrans

throwaway283719

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An anonymous drug user reveals why he regularly takes cocaine and ecstasy

theguardian.com

1 pointsby throwaway28371912 lat temu0 comments

San Francisco State of Mind

soundcloud.com

1 pointsby throwaway28371912 lat temu0 comments

comments

throwaway283719

11 lat temudiscuss

The UK soccer league is the most popular sport in the UK, and has a huge following elsewhere in Europe as well as in South America and Asia. For many of the biggest teams, the majority of their fan-base is outside of the UK. For many people, playing or watching soccer is their primary leisure activity. There are 6-10 premier league games screened each weekend across a variety of channels, not to mention the other leagues (which also have huge followings going down into the 2nd, 3rd and 4th leagues) and the various regional and international competitions that UK teams compete in, as well as the untold hours of soccer-related programming that isn't showing games.

I don't think the comparison with a hypothetical reality TV show is very meaningful.

throwaway283719

11 lat temudiscuss

It is also useful for rewriting routines in the critical path for slower, but more productive languages. Particularly languages that need to do a lot of heavy-duty data crunching (think Python, R, Matlab, Octave).

I mean, I guess you could do that in C++ instead. But why would you bother if C is good enough (and it typically is for most numerical algorithms).

throwaway283719

11 lat temudiscuss

The situation is different because there isn't a 2000+ year history of Java developers discriminating against Lisp developers.

throwaway283719

11 lat temudiscuss

In fairness, thinking that 1 is a prime number (or just not knowing that it isn't) is in quite a different league to not knowing how to calculate the average of a list of numbers.

throwaway283719

11 lat temudiscuss

It is one of the top-ranked universities in Canada (roughly equivalent to an Ivy League university in the US, or Oxbridge in the UK).

throwaway283719

11 lat temudiscuss

Which other asset classes are you thinking of? I think that most transactions in cash equities, spot fx and futures are now done electronically.

I'm sure that a large proportion of derivative trades are still done over the phone, but that's because they tend to be (a) quite customizable and (b) quite hard to price.

It is incredible that treasuries are still traded over the phone, however, given how (relatively) easy they are to price. Even treasury futures, which are harder to price due to the basis and optionality, are mostly traded electronically, which tells me that there must be some parties with a pretty strong interest in keeping bond trading a "closed shop".

throwaway283719

11 lat temudiscuss

tptacek already responded to your previous comment about Flash Boys below [0]

[0] https://news.ycombinator.com/item?id=9045150

throwaway283719

11 lat temudiscuss

The trouble with this argument is that, on basically every exchange in the world, you do not get to find out if someone has matched with your passive order until after the trade has happened.

There is no possibility to "back away when a matching order comes in" because the first time you find out about the matching order is when you are informed about the trade that you just did!

What can happen is that a market maker will post liquidity on multiple exchanges A, B and C, and will remove their orders from exchanges B and C if they are filled on exchange A (assuming they are fast enough to do it!)

This is not shady or nefarious. In fact, it is the only way that a distributed market could possibly work.

The market maker has some finite capacity to provide liquidity (e.g. they have position limits, they need to post margin, they have certain risk tolerances). They want to maximise the chances of their orders being traded on (i.e. providing liquidity), so they post liquidity on all available markets.

When they match on one of those markets, their capacity to provide liquidity has diminished, until they manage to offset their position somewhere (either on the same market, or on a different one). Moreover, they have just received a new piece of information about the supply/demand imbalance for this particular stock. For both of these reasons, it is natural to assume that they would want to adjust the prices they are offering on other exchanges. The market cannot function any other way.

throwaway283719

11 lat temudiscuss

That would be a groupoid - http://en.wikipedia.org/wiki/Groupoid

throwaway283719

11 lat temudiscuss

No. For example, a FilePath is (after resolving a few other type aliases)

  data Root
	  = RootPosix
	  | RootWindowsVolume Char
	  | RootWindowsCurrentVolume

  data FilePath = FilePath
	  { pathRoot        :: Maybe Root
	  , pathDirectories :: [String]
	  , pathBasename    :: Maybe String
	  , pathExtensions  :: [String]
	  }

throwaway283719

12 lat temudiscuss

Would you back up your 99.9% confidence level with a bet? For example, I will send you $1 if he is convicted, and you will send me $1,000 if he is acquitted?

If not, how much would you put at risk for the chance to win $1 if he is convicted?

throwaway283719

12 lat temudiscuss

Yes. You can get significant signal attenuation (particularly at high frequencies, i.e. above 10 GHz) when it is raining.

throwaway283719

12 lat temudiscuss

The problem is that it is absolutely not a good primer on the subject, and the only way you could know this is if you have experience in electronic trading already.

If you are trying to learn about electronic / high frequency trading by reading "Flash Boys" you are actively working against yourself. You will literally be more incorrect after you have read this book.

throwaway283719

12 lat temudiscuss

What markets is this done on? On most markets that I'm aware of, there is a fee for passive trades and a fee for aggressive trades. Sometimes the fee for a passive trade is negative (a rebate) which encourages liquidity provision, but I don't know of any market that actually charges per order, and then rebates that proportionally to the liquidity providers.

One proviso is that I've never worked on US equity markets, so if this rule is in place there then I wouldn't know about it.

throwaway283719

12 lat temudiscuss

But McDonald's makes a profit every time I buy a cheeseburger from them. It's like the know the true price in advance, and set their prices so that they always make a profit.

The cheeseburger market is rigged.

throwaway283719

12 lat temudiscuss

It looks like 20-25 of the Forbes "30 under 30" are YC founders or otherwise involved in YC - is that correct?

An incredible achievement if so!

throwaway283719

12 lat temudiscuss

Most market making algorithms work like -

  Market state                                     -> price forecast
  Price forecast + other factors (risk, liquidity) -> trading decision

If you know (or have a good guess) how the algorithm works, you can work out what state of the market would lead to a price forecast in your favour, i.e. would lead to the algorithm offering liquidity at a price favourable to you.

You then manipulate the state of the market to look like that (generally this is "spoofing" or "layering"), wait for the algorithm to respond, and then take advantage of the favourable liquidity it offers.

When people calibrate their algorithms, they use real market data. Most of the time, someone isn't actively manipulating the market, so the model is not calibrated to handle those situations.

throwaway283719

12 lat temudiscuss

You generally receive a salary (dependent on what you do, what kind of firm you work for and how experienced you are, but $60-200k probably captures 95% of people) and a performance-based bonus which could be anywhere from 0x to 10x your salary, again depending on exactly what you do, how the firm performs that year, how your team performs that years, and how "close to the money" you are.

I don't think programmers in the field have an appreciably shorter lifespan than in other industries. I don't think that working in an algo trading company is intrinsically any riskier than working in any other kind of firm.

The hours tend to be longer and the work tends to be slightly more stressful than if you are working at a generic bigco, however.

throwaway283719

12 lat temudiscuss

One (slightly cynical) answer is that people like to hire people like them. Most quant types working in hedge funds are very good at brainteasers, and if other people are good at brainteasers it ticks one of the "this person is like me" boxes whilst also ticking the "this person is smart" box.

It also allows an endless pissing contest of comparing new brainteasers among your colleagues, and telling stories of helpless candidates who couldn't even manage the first gasp of a hint of an idea towards the solution.

I tend not to like extremely complex brainteasers as interview questions, and especially not ones that require an "aha" moment to solve them correctly, because mostly what you're testing for is whether the candidate has seen that question before (or one like it).

On the other hand, I am a big fan of asking relatively easy math questions (i.e. first year undergraduate) in interviews, because if I'm going to be paying someone $100k+ to work on mathematical models, I'm damn well going to make sure that they understand basic probability, statistics, calculus and linear algebra. These are a bit like fizz-buzz for quants - if the candidate can answer them it doesn't prove anything, but if they can't answer them then you can stop the interview right there.

throwaway283719

12 lat temudiscuss

Kudos for having enough doubt that your intuition was correct to actually write the simulation!

Self-doubt is a quantity often found wanting among smart people, computer programmers, and especially among the intersection ;)