When S&P announces results of the S&P 500 it is for fictional stocks: they don't have a fund of their own. They just say that if had bought these 500 stocks in 1957, and traced only on the dates that the dates/prices the index did you would have so much. This is impossible to do though (expect for the smallest investors), the very act of trading a stock changes the price. Most mutual funds have enough stock that they have to consider the effect of their trade on the price of the stock: if they want to invest in a company it is done over weeks and months to ensure the price doesn't change just as a result of their actions.
A simple example: lets say company X and Y are both on the index and they decide to merge one company X on such an such a date. In order to keep 500 stocks in the index S&P has to choose something to replacement. You don't have to be very smart to see that X and Y are in talks about merging months in advance. It isn't hard to figure that the stock S&P chooses will be one of a few: Buy a bunch of them each at today's prices. When the merge happens all those index funds now buy the replacement stock which drives the price up, you have shares at an inflated price to sell to those funds. (You have figure out when to sell the stocks that were not added - but S&P is unlikely to add a bad stock so as an investment these are likely to do okay). This is easy if the index funds try to hold exactly what the S&P 500 has in it.
Because of the above index funds promise to mirror the S&P500 results, but not the actual stocks. It is easy to say mirror results, it is much harder to pull that off, even if we ignore those above who are trying to cheat you, index funds tend to be the largest funds (because they do so well they are popular!) which means most of your trades will affect the price of the stock.
There is a lot more involved (much of it that I don't know), but the above is a simple example that will get you on the right track of thinking.
No you can't. You can only buy a stock based on the set of offers to sell that stock. The closing price is the just the price that marked the last trade of the day, and isn't otherwise special.
Of course you can buy at the closing price. There are MOC and LOC orders for doing just that (Market On Close and Limit On Close).
The former indicates that you must get your order filled at the closing price, the latter allows you to specify a limit at which you'll go to, in order to trade at the closing price.
How else would funds that need to trade at the closing price, actually trade at the closing price?
Now you may not like the closing price, but that's another story.
> The closing price is the just the price that marked the last trade of the day, and isn't otherwise special.
I guess i should also point out that many ETF's mark their value based on the closing prices of the NYSE or Nasdaq making their closing prices very important.
Those are still just ordinary trades that happen at the end of the day. You're still just pulling orders off of the queue of sell orders if you're buying. The final close price will of course be the price after these trades are executed, and you aren't guaranteed to even get the close price.
> Those are still just ordinary trades that happen at the end of the day. You're still just pulling orders off of the queue of sell orders if you're buying. The final close price will of course be the price after these trades are executed, and you aren't guaranteed to even get the close price.
I'm pretty sure at this point I'm being trolled but just in case you are being serious and don't know how to google......
Are you disputing that if you issue such a trade that you are not guaranteed to be able to execute it? Because, I assure you, there is no such guarantee. I'm not even sure why this requires some special explanation. There have to be enough people willing to trade at that price. The exchange isn't going to force people to trade with you.
hold on, let me have some time to adjust for all the goal post moves you've done here.
> No you can't. You can only buy a stock based on the set of offers to sell that stock
First you said that you can't buy/sell at the closing price and I showed you that this is wrong. Infact there are a whole lot of people who are obligated to trade at the closing price
Then you said the closing price wasn't special. This as well was shown to be false as many ETF's are marked by the closing prices of certain markets, notably the NYSE.
Then you said you aren't guaranteed to get the closing price. This was an even stranger error as the message before I showed you the MOC order which indicates that you will trade at the closing price.
Finally you tripled down on this mistake by changing your argument that technically there might not be any trading partner at the close.
This is technically true that in theory it might happen, but in practice I'll sit and wait for you to find me a case where this happened.
I mean think about it. You put out an MOC order that indicates you need to get a buy order filled. Unless you are trying to buy some crazy amount of shares, you will get filled. depending on the price the closing price can move up to 10% or 20%. This means that an arbitrager can pick up shares on the cheap or sell them for an artificially high price.
The system just works.
I get that you don't work in finance but you continue to keep making the same false statements over and over again:(
You're being intentionally obtuse, for what, internet points?
> kgwgk: But you can trade at the closing price, which is the one used by S&P to do their numbers, can't you?
> readams: No you can't. You can only buy a stock based on the set of offers to sell that stock
readams is unequivocally correct here. You can attempt to trade at the closing price, but doing so is entirely at the mercy of whether or not enough open offers exist to sell that stock.
> chollida1: Then you said the closing price wasn't special. This as well was shown to be false as many ETF's are marked by the closing prices of certain markets, notably the NYSE.
This point by readams is also true. The closing price of a stock isn't special — it's, as (s)he said, simply the price of the last trade of the day. The fact that some ETFs are marked by the price of market close makes their trading price "special", but that doesn't imply anything particular about the closing price of the asset(s) they're based on.
> chollida1: Then you said you aren't guaranteed to get the closing price. This was an even stranger error as the message before I showed you the MOC order which indicates that you will trade at the closing price.
Again, readams is correct. You're guaranteed to get the closing price if and only if there are open orders at that price. Which is a big if and only if, and not actually a guarantee.
> chollida1: Finally you tripled down on this mistake by changing your argument that technically there might not be any trading partner at the close. This is technically true that in theory it might happen, but in practice I'll sit and wait for you to find me a case where this happened.
Consider the context of this entire conversation: index funds that manage billions in assets. If you don't think they can utterly exhaust open buy/sell orders at market close for any trade they need to execute to track their index, you've lost your mind. This whole thread was about how these funds have to strategically place their orders to track the underlying index as faithfully as possible, without losing their shirts to vultures who know that large funds have to execute certain orders to stay on track.
> This point by readams is also true. The closing price of a stock isn't special — it's, as (s)he said, simply the price of the last trade of the day. The fact that some ETFs are marked by the price of market close makes their trading price "special", but that doesn't imply anything particular about the closing price of the asset(s) they're based on
The closing price is special -- there's a special procedure to set the price and determine which orders execute (quite similar to the opening procedure), NYSE has a closing auction, NASDAQ has a closing cross, I'm sure most other exchanges have similar.
If there's no market/limit on close orders for a given stock, then the closing price would be the last trade; presumably the same for a stock which had its trading halted earlier in the day.
Indeed it is, thanks for posting. It always surprises me how when you get down to the nitty gritty of how financial markets work there is a lot of hidden complexity to the mechanics that could have a significant affect on how you should trade.
Right, that was kind of my point as the parent seemed to be implying you could perform an arbitrary amount of trades at the closing price and would be somehow magically guaranteed to fill the orders. Or at least that's how I read it. Interesting discussion nonetheless.
> Securities that are ineligible for inclusion in the index are limited partnerships, master limited partnerships, OTC bulletin board issues, closed-end funds, ETFs, ETNs, royalty trusts, tracking stocks, preferred stock, unit trusts, equity warrants, convertible bonds, investment trusts, ADRs, ADSs and MLP IT units
Limitations on exchanges:
> The securities must be publicly listed on either the NYSE or NASDAQ.
And of course the actual selection criteria is even more elaborate.
"Attempting a comeback" is a completely different task that usual, though.
When you're winning, a good move has a mathematical definition; it's a move that, given optimal play by both sides, will lead to victory for you. Computers aren't powerful enough to be able to calculate exactly what moves those are, but it's at least well-defined in a way that they know what they're looking for.
When you're losing, there's zero moves that, given optimal play by both sides, will lead to victory for you (so all moves are equally "bad" in a mathematical sense). Instead, "attempting a comeback" involves hoping your opponent will mess up some way, so in that sense, what constitutes a good move isn't mathematical but more about predicting how your opponent thinks and where they might mess up.
AlphaGo has mostly trained by playing itself, so the ways it thinks its opponent might mess up are probably completely different from how an actual human messes up.
Speculating that the reinforcement learning phase reinforced all the best winning strategies but had few examples of weak positions out of which the AI had to fight.
AlphaGo lost half the games it played against itself, so it's not like it doesn't have millions of training examples. However maybe it didn't learn very well how to recover once it's losing, but rather concentrated on learning how to avoid that in the first place.
Thanks for looking this up. I did some research many years ago when I was in an unpleasant on-call situation (unreliable third-party dependency) and negotiated pay for it as a result. I recall seeing a $3500 daily rate figure at the time for a cardio surgeon, but that may have been an outlier.
While the numbers may be off, one point I didn't make in my initial post but should have is that anybody doing on-call is providing a valuable service. It's no different than paying a babysitter to watch TV while your kids sleep. Both babysitters and devops/IT/whatever are compensated for their ability to act in case the unexpected happens. If someone's not getting paid for that, then it must not be valuable to the company to have that coverage.
Yeah, the article linked there is nicely specific. From the article (and these are median):
Neurological surgeons had the highest median daily rate for providing on-call coverage, about $2,000 a day. Near the top of the pay scale were neurologists ($1,500), cardiovascular surgeons ($1,600), internists ($1,050), and anesthesiologists ($800).
Among the specialists earning lower median daily rates for on-call compensation were: psychiatry ($500), general surgery ($500) gastroenterology ($500), ophthalmology ($300), and family medicine without obstetrics ($300), according to the MGMA survey data.
