I'm trying to understand the difference ETFs and index funds in terms of selling them (if you want to get rid off them quickly for any reason).  As far as I understand, if you want to sell an index fund you know 100% sure that you will sell it the same day to request it, when the market closes (so you might need to wait some hours, with all the fluctuation that might involve).  On the other hand, ETFs are traded like stocks, so if you want to sell it you might find that no one wants to buy it. If you need to sell your ETF fast because of an emergency, you might have problems. This is the reason you need to pay attention to the ETF's bid-ask spread, to be aware if you will find easy to sell it if you need (if the ask is high, many people will be willing to buy when you want to sell).  Is the above correct, specially in terms of the problems you might have when you want to sell?
Many companies offer index funds and ETFs. If two funds or ETFs track the same fund, what differentiates the two? Is it common for one index fund to outperform another? How can this happen if the funds/ETFs are tracking the same index?  I found . When forced to choose between them, index ETFs look like the better option (under the right circumstances), but what differentiates index funds/ETFs when compared to similar vehicles?
Find and extract a number from a string By Cauchy's theorem, if a prime number $p$ divides the order of a group $G$, then there is an element $g$ in $G$ whose order is $p$. In addition, if $|G|$ admits a prime decomposition with a factor $p^k$, then Sylow's theorem tells us that a subgroup of order $p^k$ must exist.   My question is the following. If $|G|$ admits a prime decomposition with a factor $p^k$, does this imply that an element of order $p^k$ must exist in $G$?   Update: As explained in Mindlack's answer (among others), the implication does not hold and simple counterexamples exist. In the comments, Mindlack discusses special cases where such an element exists. How many arrangement of the letters in MISSISSIPPI have at least 2 adjacent S's?  I was thinking that I can glue two of the S's together, so there will be 9 letters plus the special letter SS, and the number of arrangements will be $10!/(2!2!4!)$, this is not the correct answer, but what is wrong with my reasoning.  (the correct answer is $11!/(4!4!2!)-7!/(4!2!)\binom{8}{4}$, I understand the solution) MWE for externalize + automatic recompilation after tikz figure modification Why should the Standard Model be renormalizable? Effective theories like Little Higgs models or Nambu-Jona-Lasinio model are non-renormalizable and there is no problem with it, since an effective theory does not need to be renormalizable. These theories are valid until a scale $\Lambda$ (ultraviolet cutoff), after this scale an effective theory need a UV completion, a more "general" theory.  The Standard Model, as an effective theory of particle physics, needs a more general theory that addresses the phenomena beyond the Standard Model (an UV completion?). So, why should the Standard Model be renormalizable? Javascript Array.sort implementation? Which algorithm does the JavaScript Array#sort() function use?  I understand that it can take all manner of arguments and functions to perform different kinds of sorts, I'm simply interested in which algorithm the vanilla sort uses. Is it appropriate to put a comma before "which"? On Server Fault, we were discussing  in chat. There are non-native speakers in the chat and somehow we got on the topic of grammar and proper use of commas.   The sentence of interest:     I have just got a new Ubuntu LAMP VPS server, which I am trying to configure.   Some people thought that the comma was superfluous. Others did not.   When is it appropriate for a comma to preceed the word which, and is the example sentence above correct?    Also, before you vote to close this question as a dupe of , please consider the differences between the two questions and ignore the similarity of the titles. The OP's example sentence was restructured in that question instead of addressing the proper use of commas. If I have random variables $X_1,X_2,\ldots,X_n$ that are Poisson distributed with parameters $\lambda_1, \lambda_2,\ldots, \lambda_n$, what is the distribution of $Y=\left\lfloor\frac{\sum_{i=1}^n X_i}{n}\right\rfloor$ (i.e. the integer floor of the average)?  A sum of Poissons is also Poisson, but I am not confident enough in statistics to determine if it is the same for the case above. When is the union of a family of subspaces of a vector space also a subspace? It is not difficult to prove that the union of a chain (or, more generally, a directed family) of subspaces of a vector space $V$ is a subspace of $V$.   Given a family $\mathcal{F}$ of subspaces of a vector space $V$ such that the union of $\mathcal{F}$ is a subspace of $V$, is it true that $\mathcal{F}$ is a directed family?  If not, is there a "nice" characterization of families of subspaces whose union is a subspace? $a\mid b,c\mid d\Rightarrow\,\gcd(a,c)\mid \gcd(b,d)$ So far I have that $a|b$ implies $b=ax$ for some x in the integers and $c|d$ implies that $d=cy$ for some y in the integers.  From here I can see that $gcd(a,c)|gcd(b,d)$ is logically equivalent to $gcd(a,c)|gcd(ax,cy)$ but I am not sure where to go from there. What fallacy dismisses a conclusion because supporters give invalid arguments for it? There have been several discussions regarding code-only answers (answers that contain only code blocks with no textual explanation whatsoever):         Personally, I can't see why the quality filter should let such answers through at all. The main problem I have with code-only answers, especially once they're flagged as not an answer or very low quality, is that we can't determine at a glance whether these answers are:   Genuinely attempting to answer the question  answers Trying to correct an error in the question without actually answering it Random code dumps that may or may not relate to the question even by programming language or keyword(s) in the question   In particular, what exactly is an "informative code-only answer"? Does it mean the code is self-documenting? Does it mean the code substitutes code comments for a proper write-up? This is all very fuzzy. From  to the last question above:     I have never seen a code-only answer that couldn't be made better with the addition of appropriate text. They are of lower-quality than the same answer with some text.   This text makes all the difference, IMO, between an answer and a non-answer. Without it, it's often needlessly difficult to tell.  Existing code-only answers that are good-faith attempts to answer the question should be edited or downvoted, yes. But if the quality filter already tries to block code-only questions, why not block code-only answers too? These answers are often low quality, and (almost) always have ample room for improvement, just like questions. How to best encapsulate monetary values in a database Origin of the Mustache Twirling Villain Whenever someone thinks about silent cinema the image of the laughing villain, twirling his mustache, and tying the hapless blonde beauty to the railroad, pops up in our collective memory. But in which movie (or movies) did that particular image first appear? Global keyboard capture in C# application I want to capture a keyboard shortcut in my application and trigger a dialog to appear if the user presses a keyboard combo even outside of the app. Similar to Google Desktop Search's Ctrl, Ctrl to bring up the search dialog.  I have tried using some keyboard hook modules out there that basically use Win32 interop to get this effect but each implementation I've tried ties down the keyboard to some extent to where you start getting weird behaviors when the application is doing something intensive. Such as loading a large amount of data, this would cause the keyboard and mouse to lockup.  I'm looking for a lightweight solution that would allow this to be done without tying down the keyboard and mouse. In my case I'm talking about Assassin's Stance, but I'd like to know the answer for stances in general.  I feel like I might be missing something incredibly obvious caused by missing a word or two (or a paragraph), but I can't find anything that explicitly states whether or not I can use the Tome of Battle stances with ranged weapons like the bow (or crossbow).  I realize that half the classes have "blade" in their names so using ranged weapons is not in the spirit of things, but I'm looking for an explicit answer (or as close to one as possible) from any WotC official resource. If this has already been answered I'm sorry, but I could not find the answer myself from searching. I wanna transfer some files from this PC with Ubuntu to a PC with Windows 7 I don't care how to do it (ftp, samba or whatever) I wanna know the steps, I searched a lot but I can't find anything that works. Thank you. Why do we need multiple approvers for suggested edits? I already have the "Edit Questions And Answers" privilege. Yet, if I approve someone else's edit, I'm told that more votes will be required before the edit is accepted.  This seems a bit peculiar to me, since I could just copy the edited version and paste it myself. Calculate all integer solutions $(x,y,z)\in\mathbb{Z}^3$ of the equation $x^2+y^2+z^2 = 2xyz$.   My Attempt:  We will calculate for $x,y,z&gt;0$. Then, using the AM-GM Inequality, we have  $$ \begin{cases} x^2+y^2\geq 2xy\\ y^2+z^2\geq 2yz\\ z^2+x^2\geq 2zx\\ \end{cases} $$  So $x^2+y^2+z^2\geq xy+yz+zx$. How can I solve for $(x,y,z)$ after this? My ListView (of my ViewFilipper) fills the parent and buttons on the bottom get hidden