What exactly happens during a settlement period?
"Securities clearing and settlement is a complex topic - you can start by browsing relevant Wikipedia articles, and (given sufficient quantities of masochism and strong coffee) progress to entire technical books. You're correct - modern trade settlement systems are electronic and heavily streamlined.  However, you're never going to see people hand over assets until they're sure that payment has cleared - given current payment systems, that means the fastest settlement time is going to be the next business day (so-called T+1 settlement), which is what's seen for heavily standardized instruments like standard options and government debt securities. Stocks present bigger obstacles.  First, the seller has to locate the asset being sold & make sure they have clear title to it... which is tougher than it might seem, given the layers of abstraction/virtualization involved in the chain of ownership & custody, complicated in particular by ""rehypothecation"" involved in stock borrowing/lending for short sales... especially since stock borrow/lending record-keeping tends to be somewhat slipshod (cf. periodic uproar about ""naked shorting"" and ""failure to deliver""). Second, the seller has to determine what exactly it is that they have sold... which, again, can be tougher than it might seem.  You see, stocks are subject to all kinds of corporate actions (e.g. cash distributions, spin-offs, splits, liquidations, delistings...)  A particular topic of keen interest is who exactly is entitled to large cash distributions - the buyer or the seller?  Depending on the cutoff date (the ""ex-dividend date""), the seller may need to deliver to the buyer just the shares of stock, or the shares plus a big chunk of cash - a significant difference in settlement.  Determining the precise ex-dividend date (and so what exactly are the assets to be settled) can sometimes be very difficult... it's usually T-2, except in the case of large distributions, which are usually T+1, unless the regulatory authority has neglected to declare an ex-dividend date, in which case it defaults to standard DTC payment policy (i.e. T-2)... I've been involved in a few situations where the brokers involved were clueless, and full settlement of ""due bills"" for cash distributions to the buyer took several months of hard arguing. So yeah, the brokers want a little time to get their records in order and settle the trade correctly." During the settlement period, the buyer transfers payment to the seller and the seller transfers ownership to the buyer. This is really a holdover from the days when so much of stock trading was done by individual human traders, and computers were still not a huge part of the operation.  Back then, paper tickets for trades exchanged hands, and the time period was actually 5 days, so 3 days is an improvement.   A settlement period was necessary for everyone to figure out their trades and do what was necessary to make the settlements happen, so it was not always a quick process, mainly because of smaller trading firms that didn't have technology to help them along. Nowadays, technology makes settlements easy, and they usually occur at the end of the trading day.  The trading firms sum up their trades, figure out who they owe, and send lump sum settlements to the counterparties to their trades.  If anything, the 3-day period may just be used now to let parties verify trades before settling. I hope this helps. Good luck!
"The settlement date for any trade is the date on which the seller gets the buyer's money and the buyer gets the seller's product.  In US equities markets the settlement date is (almost universally) three trading days after the trade date.  This settlement period gives the exchanges, the clearing houses, and the brokers time to figure out how many shares and how many dollars need to actually be moved around in order to give everyone what they're owed (and then to actually do all that moving around). So, ""settling"" a short trade is the same thing as settling any other trade.  It has nothing to do with ""closing"" (or covering) the seller's short position. Q: Is this referring to when a short is initiated, or closed? A: Initiated.  If you initiate a short position by selling borrowed shares on day 1, then settlement occurs on day 4.  (Regardless of whether your short position is still open or has been closed.) Q: All open shorts which are still open by the settlement date have to be reported by the due date. A: Not exactly.  The requirement is that all short positions evaluated based on their settlement dates (rather than their trade dates) still open on the deadline have to be reported by the due date. You sell short 100 AAPL on day 1.  You then cover that short by buying 100 AAPL on day 2. As far as the clearing houses and brokers are concerned, however, you don't even get into the short position until your sell settles at the end of day 4, and you finally get out of your short position (in their eyes) when your buy settles at the end of day 5. So imagine the following scenarios: The NASDAQ deadline happens to be the end of day 2.  Since your (FINRA member) broker has been told to report based on settlement date, it would report no open position for you in AAPL even though you executed a trade to sell on day 1. The NASDAQ deadline happens to be the end of day 3.  Your sell still has not settled, so there's still no open position to report for you. The NASDAQ deadline happens to be the end of day 4.  Your sell has settled but your buy has not, so the broker reports a 100 share open short position for you. The NASDAQ deadline happens to be the end of day 5.  Your sell and buy have both settled, so the broker once again has no open position to report for you. So, the point is that when dealing with settlement dates you just pretend the world is 3 days behind where it actually is." At the bottom of the page you linked to, NASDAQ provides a link to this page on nasdaqtrader.com, which states Each FINRA member firm is required to report its “total” short interest positions in all customer and proprietary accounts in NASDAQ-listed securities twice a month. These reports are used to calculate short interest in NASDAQ stocks. FINRA member firms are required to report their short positions as of settlement on (1) the 15th of each month, or the preceding business day if the 15th is not a business day, and (2) as of settlement on the last business day of the month.* The reports must be filed by the second business day after the reporting settlement date. FINRA compiles the short interest data and provides it for publication on the 8th business day after the reporting settlement date. The dates you are seeing are the dates the member firms settled their trades. In general (also from nasdaq.com), the settlement date is The date on which payment is made to settle a trade. For stocks traded on US exchanges, settlement is currently three business days after the trade. What typically happens to brokerage accounts during similar situations? This depends on country, time and situation. Nothing is predictable in such situations. In Greece during the said period the stock exchanges were closed for 5 weeks. There was no trading.  Edits: Every situation is different and it would be unfair to compare one against another or use it to predict something else. Right now in India due to demonitization, cash withdrawal is limited. One can trade in stocks, unlimited bank transfers, transfer money out of India ...etc. Everything same except for cash withdrawal. In 1990, the ASEAN countries survived a financial collapse, everything was allowed except moving money out of country. No, you cannot withdraw the money until settlement day. Some brokers will allow you to trade with unsettled funds, but you cannot withdraw it until it is settled.  Think about it, when you buy stock you have to pay for them by T+3, so if you sell you actually don't receive the funds until T+3. You have to call Interactive Brokers for this. This is what you should do, they might even have a web chat. These are very broker specific idiosyncrasies, because although margin rules are standardized to an extent, when they start charging you for interest and giving you margin until settlement may not be standardized. I mean, I can call them and tell you what they said for the 100 rep. Looks like the result got decided recently, with a little uncertainty about exactly how much is the total allowed claims: http://www.wilmingtontrust.com/gmbondholders/plan_disclosure.html http://www.wilmingtontrust.com/gmbondholders/pdf/GUC_Trust_Agreement.pdf They give the following example: Accordingly, pursuant to Section 5.3 of the GUC Trust Agreement, a holder of a Disputed Claim in the Amount of $2,000,000 that was Allowed in the amount of $1,000,000 (A) as of the end of the first calendar quarter would receive: Corresponding to the Distribution to the Holders of Initial Allowed Claims: Corresponding to the First Quarter Distribution to Holders of Units: Total: "Ignoring the complexities of a standardised and regulated market, a futures contract is simply a contract that requires party A to buy a given amount of a commodity from party B at a specified price. The future can be over something tangible like pork bellies or oil, in which case there is a physical transfer of ""stuff"" or it can be over something intangible like shares. The purpose of the contract is to allow the seller to ""lock-in"" a price so that they are not subject to price fluctuations between the date the contract is entered and the date it is complete; this risk is transferred to the seller who will therefore generally pay a discounted rate from the spot price on the original day. In many cases, the buyer actually wants the ""stuff""; futures contracts between farmers and manufacturers being one example. The farmer who is growing, say, wool will enter a contract to supply 3000kg at $10 per kg (of a given quality etc. there are generally price adjustments detailed for varying quality) with a textile manufacturer to be delivered in 6 months. The spot price today may be $11 - the farmer gives up $1 now to shift the risk of price fluctuations to the manufacturer. When the strike date rolls around the farmer delivers the 3000kg and takes the money - if he has failed to grow at least 3000kg then he must buy it from someone or trigger whatever the penalty clauses in the contract are. For futures over shares and other securities the principle is exactly the same. Say the contract is for 1000 shares of XYZ stock. Party A agrees to sell these for $10 each on a given day to party B. When that day rolls around party A transfers the shares and gets the money. Party A may have owned the shares all along, may have bought them before the settlement day or, if push comes to shove, must buy them on the day of settlement. Notwithstanding when they bought them, if they paid less than $10 they make a profit if they pay more they make a loss.  Generally speaking, you can't settle a futures contract with another futures contract - you have to deliver up what you promised - be it wool or shares." Brokerage firms must settle funds promptly, but there's no explicit definition for this in U.S. federal law. See for example, this article on settling trades in three days. Wikipedia also has a good write-up on T+3. It is common practice, however. It takes approximately three days for the funds to be available to me, in my Canadian brokerage account. That said, the software itself prevents me from using funds which are not available, and I'm rather surprised yours does not. You want to be careful not to be labelled a pattern day trader, if that is not your intention. Others can better fill you in on the consequences of this. I believe it will not apply to you unless you are using a margin account. All but certainly, the terms of service that you agreed to with this brokerage will specify the conditions under which they can lock you out of your account, and when they can charge interest. If they are selling your stock at times you have not authorised (via explicit instruction or via a stop-loss order), you should file a complaint with the S.E.C. and with sufficient documentation. You will need to ensure your cancel-stop-loss order actually went through, though, and the stock was sold anyway. It could simply be that it takes a full business day to cancel such an order. The original option writer (seller) can close his short position in the contracts he wrote by purchasing back matching contracts (i.e. contracts with the same terms: underlying, option type, strike price, expiration date) from any others who hold long positions, or else who write new matching contract instances. Rather than buyer and seller settling directly, options are settled through a central options clearing house, being the Options Clearing Corporation for exchange-listed options in the U.S. See also Wikipedia - Clearing house (finance). So, the original buyer of the put maintains his position (insurance) and the clearing process ensures he is matched up with somebody else holding a matching obligation, if he chooses to exercise his put. I also answered a similar question but in more detail, here. If you participate, you will either get some money or some other renumeration. If you do not participate, you will not get anything. The only risk of participating is that if you have suffered actual damages, the settlement may under-compensate you. By significant, I mean thousands of dollars, since bringing suit yourself would be very expensive. Unless you can demonstrate that you have suffered from significant damages as a result of MBNA's bad behavior, joining the class to get whatever you are going to get is almost certainly a no-brainer decision. Typically there are several parties involved: (Sometimes one company plays multiple roles; for example AmEx is a network and an issuer.) When a merchant charges a card and the issuer approves it, money is transferred from the issuer to the acquirer to the merchant. This settlement process takes some time, but generally is completed within a day. Of course, most cardholders pay on a monthly basis. The issuer must use their own funds in the mean time. If the cardholder defaults, the issuer takes the loss. The T+3 settlement date only affects cash accounts.  In a cash account, you need to wait until the T+3 settlement date for your funds to be available to make your next trade.  But if you convert your cash account into a margin account, then you do not need to wait until the T+3 settlement date for your next trade - your broker will allow you to make another trade immediately. I used to work on the software in the front office (and a bit of the middle office) of a brokerage firm. This page describes the process pretty well. Basically there are three parts: So to your question: how does an order get executed? ETFs work the same since they are effectively shares of a mutual fund's assets. True mutual fund shares work differently since they don't get traded in the market. They get traded at the end of the market as just a bookkeeping exercise. Let P denote the amount of the investment, R the rate of return and I the rate of inflation.  For simplicity, assume that the payment p is made annually right after the return has been earned.  Thus, at the end if the year, the investment P has increased to P*(1+R) and p is returned as the annuity payment. If I = 0, the entire return can be paid out as the payment, and thus p = P*R. That is, at the end of the year, when the dust settles after the return P*R has been collected and paid out as the annuity payment, P is again available at the beginning of the next year to earn return at rate R. We have P*(1+R) - p = P If I > 0, then at the end of the year, after the dust settles, we cannot afford to have only P available as the investment for next year. Next year's payment must be p*(1+I) and so we need a larger investment since the rate of return is fixed.  How much larger?  Well, if the investment at the beginning of next year is P*(1+I), it will earn exactly enough additional money to pay out the increased payment for next year, and have enough left over to help towards future increases in payments. (Note  that we are assuming that R > I. If R < I, a perpetuity cannot be created.)  Thus, suppose that we choose p such that P*(1+R) - p = P*(1+I)   Multiplying this equation by (1+I), we have [P(1+I)]*(1+R) - [p*(1+I)] = P*(1+I)^2 In words, at the start of next year, the investment is P*(1+I) and the return less the increased payout of p*(1+I) leaves an investment of P*(1+I)^2 for the following year.  Each year, the payment and the amount to be invested for the following year increase by a factor of (1+I). Solving P*(1+R) - p = P*(1+I) for p, we get  p = P*(R-I)  as the initial perpetuity payment and the payment increases by a factor (1+I) each year.  The initial investment is P and it also increases by a factor of (1+I) each year. In later years, the investment is P*(1+I)^n at the start of the year, the payment is p*(1+I)^n and the amount invested for the next year is P*(1+I)^{n+1}. This is the same result as obtained by the OP but written in terms that I can understand, that is, without the financial jargon about discount rates, gradients, PV, FV and the like. I wish this was the case in Canada.  I lost about 60k on my home in one year and have to sell now to move for work.    In the US I could simply default and the bank takes the loss.  In Canada if I default, CMHC pays the bank, then I'm sued by CMHC and stuck with the bad debt.    Simply put - here the onus of repayment is on the lender, not the lending institution.  It sounds good until you are the one looking at losing your shirt.