I'd imagine they calculate latency from the time a market order hits their system, to the time it gets executed. An order comes in (UDP message), they do timestamp1, walk the book (heap or balanced tree) to find a match. if match found, `execute' if no match, add order to book. either way, generate an output message and add it to "out" queue [that happens at almost identical time as the original order arrival time]. The output process picks up thing from queue, and does timestamp2 (either order executed, or is now sitting on the book). No network or disk I/O is involved in such latency numbers. The output process sends outgoing UDP message and forward message to another thread to persist the event in database.
If they do things very carefully, they may manage to do input (read message, walk book, and place structure in output queue), and have output process pick it up on the *next* time slice... having the order turn around time in their system be very low. OS is probably irrelevant, but I'd imagine them having a lot more control over such detailed scheduling on Linux... (e.g. having OS interrupt you in middle of walking your book can double or quadruple your turn around time).
Here's an industry related question, how does high frequency trading benefit the general public? The push towards regnms, the push towards faster and faster executions---how does all this benefit Joe Investor? What is SEC thinking?
I doubt Joe Investor cares if his trade executes within a microsecond or in a few minutes. I even doubt he cares that much about the 1% price difference he may enjoy (or regret) from his investment within a week.
So why is everyone in the industry assuming Joe Investor is a day-trader with an algorithm at his desk? Even the active investors I've met keep stocks for sometime---the only "day-traders" I've met aren't in the investment business---they're there to benefit from minute-by-minute price fluctuation---leaching (by tiny amounts) the profits of long term participants.
I guess what I'm saying is, if high frequency trading is a billion dollar industry---those billions of dollars, in small amounts, were directly taken out of pockets of long-term investors---they're the inefficiency in the market.
I'd imagine folks with any ideals and power have long since (unofficially?) retired from any management decisions that are to be made---and now it's all about sucking the most out of this cash cow as possible for the folks who are left. This happened at many corps before.
That's why those camera-related tickets are treated as a non-moving violating (eg. equivalent to parking ticket). If your car gets a parking ticket, it doesn't matter who parked it... same with the camera.
while I do agree with your point, another possibility is that employed (in the industry) scientists, on average, are smarter (or better equipped) than those in the academia. e.g. Most scientists would jump at a chance to work for an oil corp.
Without internet, there's no "work" for me to go to. My internet is my phone, and pretty much my only way to communicate and get news. You think your bank will operate without internet?
Shutting it down to prevent a disaster? Eh? Shutting it down *is* the disaster. Doing it for 120 days... that's just INSANE. These are the folks who are running this country???
hate to break it to you, but that "$89 billion lost" includes a hefty portion of "future growth" assumption. e.g. how optimistic you are about BP's future. it's a made up number by crowds on wall st.
BP haven't ``lost'' $89 billion---they never had it.
Neither does Android. To this day. Yes, sure, you can cut and paste things where "they let you", but something stupidly simple like... say copying and pasting a UPS code from your email into a web-browser... is well beyond the capabilities of your Android phone.
-happy owner of NexusOne---hopefully they'll figure it out, eventually.
Maybe one way nature avoids paradoxes is by simply not allowing the past to see the future---but not the other way around? That would mean you could have time travelers, but we would be unaware of them (and they'd have no way of altering things that have consequences to their existence). Sort of like the ability to view a very detailed recording of history...
Not a python fan myself, but what would be the downside of rewriting gcc in python?.
via cross-compilation, you can still make a binary for any platform you like---and it's probably much easier to work with and maintain than a ton of C/C++ code.
Regression analysis depends on a few *past* samples. So lets say you use last 5 trades (or last 5 or 20 minutes of trades?) to find the direction---problem is... you now know where it "was" not where it will be in the next 5 minutes. ie: even short term, stock prices are fundamentally tricky to even guess right (nobody has managed to do it with better than 50% chance). Not to mention that trade by trade prices are between the spread---making regression a bit trickier if you're dealing with pennies.
Totally agree, except... imagine a publicly traded trading firm... all of a sudden their ``fundamentals'' are tied to how well they swindle other traders---suddenly even savvy investors will consider them (and their profits) for long term investment. It's like a self feeding loop...
eg, Warren bought a chunk of Goldman... what exactly does Goldman make---besides being the cleverest (and profitable) firm on the block?
This has nothing to do with perpetual growth---this is day trading, nothing to do with fundamentals. What this is about is being more clever than the next guy... and there, there's real potential for perpetual growth (you can have all the money in the world, and for the rest, they can have an infinitely increasing debt forever---as long as you're more clever than them).
I'd imagine in an advanced enough society, ``cost'' becomes irrelevant (when you have an option to live in total comfort your whole life without working, etc.), and other things like ``lets do this for fun'' become a lot more important.
So yes, their primary mission (at the moment) may be to just stop by and say "hi". Maybe pull a joke or two. And it may not matter that it took them unimaginable (by our standards) resources to do that simple stupid thing.
So you're saying instead of smelting metal, making concrete, and paying construction workers to build the battery, it might be more cost effective to pay that same smelting facility, concrete making plant, and construction workers to provide a few hours of power for this town every week or so?
I doubt this project has anything to do with "renewable" but all to do with convenience of not having to lose power for a few hours every few weeks. Sure those few hours may be 10x as expensive as normal, but, eh, you don't have to adjust clocks on all those VCRs every week.
Well, in that scenario the owners (shareholders) of Pfizer would've suffered big time---and that's exactly what the punishment for a company should be!
(granted, the shareholders were not directly involved in the crime; but they sure as heck benefited from it via stock price, etc.)
you do of course realize that number of job postings is inversely proportional to the $$$ a developer makes. ie: I'd imagine those cobol developers making $200k/year vs $50k/year for those gazillion Java job postings.
Slashdot Mirror
I'd imagine they calculate latency from the time a market order hits their system, to the time it gets executed. An order comes in (UDP message), they do timestamp1, walk the book (heap or balanced tree) to find a match. if match found, `execute' if no match, add order to book. either way, generate an output message and add it to "out" queue [that happens at almost identical time as the original order arrival time]. The output process picks up thing from queue, and does timestamp2 (either order executed, or is now sitting on the book). No network or disk I/O is involved in such latency numbers. The output process sends outgoing UDP message and forward message to another thread to persist the event in database.
If they do things very carefully, they may manage to do input (read message, walk book, and place structure in output queue), and have output process pick it up on the *next* time slice... having the order turn around time in their system be very low. OS is probably irrelevant, but I'd imagine them having a lot more control over such detailed scheduling on Linux... (e.g. having OS interrupt you in middle of walking your book can double or quadruple your turn around time).
Here's an industry related question, how does high frequency trading benefit the general public? The push towards regnms, the push towards faster and faster executions---how does all this benefit Joe Investor? What is SEC thinking?
I doubt Joe Investor cares if his trade executes within a microsecond or in a few minutes. I even doubt he cares that much about the 1% price difference he may enjoy (or regret) from his investment within a week.
So why is everyone in the industry assuming Joe Investor is a day-trader with an algorithm at his desk? Even the active investors I've met keep stocks for sometime---the only "day-traders" I've met aren't in the investment business---they're there to benefit from minute-by-minute price fluctuation---leaching (by tiny amounts) the profits of long term participants.
I guess what I'm saying is, if high frequency trading is a billion dollar industry---those billions of dollars, in small amounts, were directly taken out of pockets of long-term investors---they're the inefficiency in the market.
I think what GP meant were wash sales.
I'd imagine folks with any ideals and power have long since (unofficially?) retired from any management decisions that are to be made---and now it's all about sucking the most out of this cash cow as possible for the folks who are left. This happened at many corps before.
I think it's 2 seconds.
That's why those camera-related tickets are treated as a non-moving violating (eg. equivalent to parking ticket). If your car gets a parking ticket, it doesn't matter who parked it... same with the camera.
while I do agree with your point, another possibility is that employed (in the industry) scientists, on average, are smarter (or better equipped) than those in the academia. e.g. Most scientists would jump at a chance to work for an oil corp.
non-square pixels remind me of mode 13h :-/
Without internet, there's no "work" for me to go to. My internet is my phone, and pretty much my only way to communicate and get news. You think your bank will operate without internet?
Shutting it down to prevent a disaster? Eh? Shutting it down *is* the disaster. Doing it for 120 days... that's just INSANE. These are the folks who are running this country???
hate to break it to you, but that "$89 billion lost" includes a hefty portion of "future growth" assumption. e.g. how optimistic you are about BP's future. it's a made up number by crowds on wall st.
BP haven't ``lost'' $89 billion---they never had it.
Neither does Android. To this day. Yes, sure, you can cut and paste things where "they let you", but something stupidly simple like... say copying and pasting a UPS code from your email into a web-browser... is well beyond the capabilities of your Android phone.
-happy owner of NexusOne---hopefully they'll figure it out, eventually.
Maybe one way nature avoids paradoxes is by simply not allowing the past to see the future---but not the other way around? That would mean you could have time travelers, but we would be unaware of them (and they'd have no way of altering things that have consequences to their existence). Sort of like the ability to view a very detailed recording of history...
Not a python fan myself, but what would be the downside of rewriting gcc in python?.
via cross-compilation, you can still make a binary for any platform you like---and it's probably much easier to work with and maintain than a ton of C/C++ code.
Well, the black slick will cost more than the default white one.
Nice model! The financial world can be seen as swindling folks out of their time by promising and borrowing time from the infinite future :-)
Regression analysis depends on a few *past* samples. So lets say you use last 5 trades (or last 5 or 20 minutes of trades?) to find the direction---problem is... you now know where it "was" not where it will be in the next 5 minutes. ie: even short term, stock prices are fundamentally tricky to even guess right (nobody has managed to do it with better than 50% chance). Not to mention that trade by trade prices are between the spread---making regression a bit trickier if you're dealing with pennies.
buy spam! lasts practically forever, edible---and if world economy collapses, way more useful than gold (forgot name of economist who said that).
Totally agree, except... imagine a publicly traded trading firm... all of a sudden their ``fundamentals'' are tied to how well they swindle other traders---suddenly even savvy investors will consider them (and their profits) for long term investment. It's like a self feeding loop...
eg, Warren bought a chunk of Goldman... what exactly does Goldman make---besides being the cleverest (and profitable) firm on the block?
This has nothing to do with perpetual growth---this is day trading, nothing to do with fundamentals. What this is about is being more clever than the next guy... and there, there's real potential for perpetual growth (you can have all the money in the world, and for the rest, they can have an infinitely increasing debt forever---as long as you're more clever than them).
...and at great cost to themselves
I'd imagine in an advanced enough society, ``cost'' becomes irrelevant (when you have an option to live in total comfort your whole life without working, etc.), and other things like ``lets do this for fun'' become a lot more important.
So yes, their primary mission (at the moment) may be to just stop by and say "hi". Maybe pull a joke or two. And it may not matter that it took them unimaginable (by our standards) resources to do that simple stupid thing.
...it's the chevy nova...lighting up the night sky...
---Fry
So you're saying instead of smelting metal, making concrete, and paying construction workers to build the battery, it might be more cost effective to pay that same smelting facility, concrete making plant, and construction workers to provide a few hours of power for this town every week or so?
I doubt this project has anything to do with "renewable" but all to do with convenience of not having to lose power for a few hours every few weeks. Sure those few hours may be 10x as expensive as normal, but, eh, you don't have to adjust clocks on all those VCRs every week.
Well, in that scenario the owners (shareholders) of Pfizer would've suffered big time---and that's exactly what the punishment for a company should be!
(granted, the shareholders were not directly involved in the crime; but they sure as heck benefited from it via stock price, etc.)
...the passive scanners are. Is anyone using active scanners anywhere?
you do of course realize that number of job postings is inversely proportional to the $$$ a developer makes. ie: I'd imagine those cobol developers making $200k/year vs $50k/year for those gazillion Java job postings.