Why can it be a bad idea to buy stocks after hours?
There are several reasons it is not recommended to trade stocks pre- or post-market, meaning outside of RTH (regular trading hours). Since your question is not very detailed I have to assume you trade with a time horizon of at least more than a day, meaning you do not trade intra-day. If this is true, all of the above points are a non-issue for you and a different set of points becomes important. As a general rule, using (3) is the safest regardless of what and how you trade because you get price guarantee in trade for execution guarantee. In the case of mid to longer term trading (1 week+) any of those points is viable, depending on how you want to do things, what your style is and what is the most comfortable for you. A few remarks though: (2) are market orders, so if the open is quite the ride and you are in the back of the execution queue, you can get significant slippage. (1) may require (live) data of the post-market session, which is often not easy to come by for the entire US stock universe. Depending on your physical execution method (phone, fax, online), you may lack accurate information of the post-market. If you want to execute orders based on RTH and only want to do that after hours because of personal schedule constraints, this is not really important. Personally I would always recommend (3), independent of the use case because it allows you more control over your orders and their fills. TL;DR: If you are trading long-term it does not really matter. If you go down to the intra-day level of holding time, it becomes relevant. "During market hours, there are a lot of dealers offering to buy and sell all exchange traded stocks. Dealers don't actually care about the company's fundamentals and they set their prices purely based on order flow. If more people start to buy than sell, the dealer notices his inventory going down and starts upping the price (both his bid and ask). There are also traders who may not be ""dealers"", but are willing to sell if the price goes high enough or buy if the price goes low enough. This keeps the prices humming along smoothly. During normal trading hours, if you buy something and turn around and sell it two minutes later, you'll probably be losing a couple cents per share. Outside normal market hours, the dealers who continue to have a bid and ask listed know that they don't have access to good price information --  there isn't a liquid market of continuous buying and selling for the dealer to set prices he considers safe. So what does he do? He widens the spread. He doesn't know what the market will open tomorrow at and doesn't know if he'll be able to react quickly to news. So instead of bidding $34.48 and offering at $34.52, he'll move that out to $33 and $36. The dealer still makes money sometimes off this because maybe some trader realized that he has options expiring tomorrow, or a short position that he's going to get a margin call on, or some kind of event that pretty much forces him to trade. Or maybe he's just panicking and overreacting to some news. So why not trade after hours? Because there's no liquidity, and trading when there's no liquidity costs you a lot." Unless you want to be a short term day trader, then it is not foolish to be an end of day trader. If you are looking to be a medium to long term trader/investor then it is quite acceptable to put orders in after market close. Some would say it is even less risky, because you are not watching the price fluctuate up and down and letting your emotions getting the best of you. The sentiment is because between closing and opening a lot can happen, and between opening and the time your order actually goes through, even more can happen.  An after-hours trade has an extra amount of short-term risk attached; the price of a stock at the opening bell is technically the same as its price as of the closing the previous trading day, but within a tenth of a second, which is forever in a computerized exchange, that price may move drastically one way or the other, based on news and on other markets. The sentiment, therefore, is simple; if you're trading after-hours, you're trading risky. You're not trading based on what the market's actually doing, you're trading based on what you think the market will do in the morning, and there's still more math going on every second in the privately-held supercomputers in rented cubes in the NYSE basement than you could do all night, digesting this news and projecting what it's going to do to the stocks. Now, if you've done your homework and the stock looks like a good long-term buy, with or without any after-hours news, then place the order at 3 in the morning; who cares what the stock's gonna do at the opening bell. You're gonna hold that stock for the next ten years, maybe; what it does in 5 seconds of opening turmoil is relatively minor compared to the monthly trends that you should be worrying about.
"House prices do not go up.  Land prices in countries with growing economies tend to go up.  The price of the house on the land generally depreciates as it wears out. Houses require money; they are called money pits for a reason.  You have to replace HVAC periodically, roofs, repairs, rot, foundation problems, leaks, electrical repair; and all of that just reduces the rate at which the house (not the land) loses value. To maintain value (of the house proper), you need to regularly rebuild parts of the house.  People expect different things in Kitchens, bathrooms, dining rooms, doors, bedrooms today than they do in the past, and wear on flooring and fixtures accumulate over time. The price of land and is going to be highly determined by the current interest rates.  Interest rates are currently near zero; if they go up by even a few percent, we can expect land prices to stop growing and start shrinking, even if the economy continues to grow.  So the assumption that land+house prices go up is predicated on the last 35 years of constant rigorous economic growth mixed with interest rate decreases.  This is a common illusion, that people assume the recent economic past is somehow the way things are ""naturally"".  But we cannot decrease interest rates further, and rigorous economic growth is far from guaranteed. This is because people price land based on their carrying cost; the cost you have to spend out of your income to have ownership of it.  And that is a function of interest rates.  Throw in no longer expecting land values to constantly grow and second-order effects that boost land value also go away. Depending on the juristiction, a mortgage is a hugely leveraged investment.  It is akin to taking 10,000$, borrowing 40,000$ and buying stock.  If the stock goes up, you make almost 5x as much money; if it goes down, you lose 5x as much.  And you owe a constant stream of money to service the debt on top of that. If you want to be risk free, work out how you'd deal with the value of your house dropping by 50% together with losing your job, getting a job paying half as much after a period of 6 months unemployment.  The new job requires a 1.5 hour commute from your house.  Interest rates going up to 12% and your mortgage is up for renewal (in 15 years - they climbed gradually over the time, say), optionally. That is a medium-bad situation (not a great depression scale problem), but is a realistic ""bad luck"" event that could happen to you.  Not likely, but possible. Can you weather it?  If so, the risk is within your bounds.  Note that going bankrupt may be a reasonable plan to such a bit of bad luck.  However, note that had you not purchased the house, you wouldn't be bankrupt in that situation. It is reasonably likely that house prices will, after you spend ~3% of the construction cost of the house per year, pay the mortgage on the land+house, grow at a rate sufficient to offset the cost of renting and generate an economically reasonable level of profit.  It is not a risk-free investment. If someone tries to sell you a risk-free investment, they are almost certainly wrong." "This is the sad state of US stock markets and Regulation T. Yes, while options have cleared & settled for t+1 (trade +1 day) for years and now actually clear ""instantly"" on some exchanges, stocks still clear & settle in t+3.  There really is no excuse for it. If you are in a margin account, regulations permit the trading of unsettled funds without affecting margin requirements, so your funds in effect are available immediately after trading but aren't considered margin loans.  Some strict brokers will even restrict the amount of uncleared margin funds you can trade with (Scottrade used to be hyper safe and was the only online discount broker that did this years ago); others will allow you to withdraw a large percentage of your funds immediately (I think E*Trade lets you withdraw up to 90% of unsettled funds immediately). If you are in a cash account, you are authorized to buy with unsettled funds, but you can't sell purchases made on unsettled funds until such funds clear, or you'll be barred for 90 days from trading as your letter threatened; besides, most brokers don't allow this.  You certainly aren't allowed to withdraw unsettled funds (by your broker) in such an account as it would technically constitute a loan for which you aren't even liable since you've agreed to no loan contract, a margin agreement.  I can't be sure if that actually violates Reg T, but when I am, I'll edit. While it is true that all marketable options are cleared through one central entity, the Options Clearing Corporation, with stocks, clearing & settling still occurs between brokers, netting their transactions between each other electronically. All financial products could clear & settle immediately imo, and I'd rather not start a firestorm by giving my opinion why not. Don't even get me started on the bond market... As to the actual process, it's called ""clearing & settling"". The general process (which can generally be applied to all financial instruments from cash deposits to derivatives trading) is: The reason why all of the old financial companies were grouped on Wall St. is because they'd have runners physically carting all of the certificates from building to building.  Then, they discovered netting so slowed down the process to balance the accounts and only cart the net amounts of certificates they owed each other.  This is how we get the term ""bankers hours"" where financial firms would close to the public early to account for the days trading.  While this is all really done instantly behind your back at your broker, they've conveniently kept the short hours." "It's not necessarily bad but it can cause the stock price to become a lot more volatile. Depends on which side of the bet you're on ;) Suppose a hedge fund manager thinks a company is poorly run. He may buy a ton of shares so that he can get rid of the current CEO and replace it with his/her own. For the hedge fund and others long on the stock, this is good. Those who are trading options or using some short-term strategies could get screwed because of the sudden volatility.  My next point is related to the above. What is the intrinsic value of a stock? The current price of a stock is the equilibrium of all investor's perception of the stock's value. Professionals make up a value for a stock using models such as DCF. Once they do so they trade based on what they believe the value of the stock is. You might calculate a stock is worth 70 and I believe it's 80 so the stock price is going to fluctuate a bit but it should keep within that range (assuming we're the only investors). Then comes a hedge fund manager, say Carl Icahn, and discloses a stake in our stock. ""Wow, the stock must be really valuable!"" Everyone starts buying this stock so up it goes to 90, simply because the guy who seems to know what he's doing bought it. The point here is that now it's not trading based on intrinsic value, now it's purely psychological. Ie. it's now a momentum stock, which you have no idea when it'll crash. Look at Tesla, Netflix, or just google momentum stocks. All the big crashes in stock prices happen when these big funds unload their stocks. A surge in supply will cut the price. The problem is you can't predict when some fund manager will decide to sell some stake of his.  Tying everything together is liquidity. The more liquid a stock is, the easier it is to obtain and the less volatile it is. The more people playing the game, with not too big shares of stock, the faster the price will converge to some equilibrium and with less volatility. Institutional investors take away liquidity." "You don't seem to be a big fan of trading as you may think it may be too risky or too time consuming being in front of your computer all day long. You also don't seem to be a fan of buy and hold as you don't know what your investments will be worth when you need the funds. How about a combination of the two, sometimes called trend trading or active investing. With this type of trading/investing you may hold a stock from a couple of months to many years. Once you buy a stock that is up-trending or starting to up-trend you hold onto it until it stops up-trending. You can use a combination of fundamental analysis (to find out what to buy) and technical analysis (to tell you when to buy and when to sell). So these are some topics you can start reading up on. Using a technique like this will enable you to invest in healthy stocks when they are moving up in price and get out of them when they start moving down in price. There are many techniques you can use to get out of a stock, but the simplest has to be using stop losses. And once you learn and set up your system it should not take up much of your time when you actually do start trading/investing - 2 to 3 hours per week, and you can set yourself up that you analyse the market after the close and place any order so they get executed the next trading day without you being in front or the screen all day. Other areas you might want to read and learn about are writing up a Trading Plan, using Position Sizing and Money Management so you don't overtrade in any one single trade, and Risk Management. A good book I quite liked is ""Trade Your Way to Financial Freedom"" by Van Tharp. Good luck." Short-term, the game is supply/demand and how the various participants react to it at various prices. On longer term, prices start to better reflect the fundamentals. Within something like week to some month or two, if there has not been any unique value affecting news, then interest, options, market maker(s), swing traders and such play bigger part. With intraday, the effects of available liquidity become very pronounced. The market makers have algos that try to guess what type of client they have and they prefer to give high price to large buyer and low price to small buyer. As intraday trader has spreads and commissions big part of their expenses and leverage magnifies those, instead of being able to take advantage of the lower prices, they prefer to stop out after small move against them. In practise this means that when they buy low, that low will soon be the midpoint of the day and tomorrows high etc if they are still holding on. Buy and sell are similar to long call or long put options position. And options are like insurance, they cost you. Also the longer the position is held the more likely it is to end up with someone with ability to test your margin if you're highly leveraged and constantly making your wins from the same source.  Risk management is also issue. The leveraged pros trade through a company. Not sure if they're able to open another such company and still open accounts after the inevitable. "I agree that retail looks for orderly markets, but orderly markets have really never existed. Really study market history, and you'll see that markets are more orderly today than they ever have been. The stuff that used to take place was just insane and happened before computers--let alone HFT.  Let me state that, while it may seem like I'm defending HFT, my algos are actually much longer-term and wouldn't be hurt by any of your proposals. I think many of the HFT guys are no better than those three-card monte sharks who used to fill Times Square. But they're just playing the game. They're not good, but they're also not bad; they're just another segment of players. In orderly markets (up and down), they really do add liquidity. When things go awry as they tend to do in the markets, the HFTs step aside. But don't fool yourself--market makers have always done the exact same thing. And also remember that many markets don't even have market makers; traders provide all liquidity.  Here's the thing. Retail investors swarm to the markets when everything is going up and up. They believe they can do no wrong and that prices will go up forever. Then the market gets a bit tougher, retail investors (and most ""pros,"" by the way) start to lose, and then retail investors cry foul. Markets were never intended to be a nice, safe playground for the masses. They were designed for those who dedicate their lives to understanding them. I don't pretend that I can litigate a legal case, operate on someone's brain, or build a bridge. Experts have studied those areas for decades and are quite good at those things. But retail investors have always thought of Wall Street as some sort of ""safe Las Vegas."" In reality, it's survival of the fiercest.  I'll say to you what I say to every one of my friend's who wants me to ""show them a few things about trading"": If you aren't going to really commit thousands of hours to understanding the markets, then stay out. Invest money that you don't need for some time in a few good mutual funds. Keep your debt to a minimum. Don't chase quick profits if you don't understand the game." "Most of the investors who have large holdings in a particular stock have pretty good exit strategies for those positions to ensure they are getting the best price they can by selling gradually into the volume over time. Putting a single large block of stock up for sale is problematic for one simple reason: Let's say you have 100,000 shares of a stock, and for some reason you decide today is the day to sell them, take your profits, and ride off into the sunset.  So you call your broker (or log into your brokerage account) and put them up for sale.  He puts in an order somewhere, the stock is sold, and your account is credited. Seems simple, right?  Well...not so fast. Professionals - I'm keeping this simple, so please don't beat me up for it! The way stocks are bought and sold is through companies known as ""market makers"".  These are entities which sit between the markets and you (and your broker), and when you want to buy or sell a stock, most of the time the order is ultimately handled somewhere along the line by a market maker.  If you work with a large brokerage firm, sometimes they'll buy or sell your shares out of their own accounts, but that's another story. It is normal for there to be many, sometimes hundreds, of market makers who are all trading in the same equity.  The bigger the stock, the more market makers it attracts.  They all compete with each other for business, and they make their money on the spread between what they buy stock from people selling for and what they can get for it selling it to people who want it. Given that there could be hundreds of market makers on a particular stock (Google, Apple, and Microsoft are good examples of having hundreds of market makers trading in their stocks), it is very competitive.  The way the makers compete is on price.  It might surprise you to know that it is the market makers, not the markets, that decide what a stock will buy or sell for. Each market maker sets their own prices for what they'll pay to buy from sellers for, and what they'll sell it to buyers for.  This is called, respectively, the ""bid"" and the ""ask"" prices.  So, if there are hundreds of market makers then there could be hundreds of different bid and ask prices on the same stock.  The prices you see for stocks are what are called the ""best bid and best ask"" prices.  What that means is, you are being shown the highest ""bid"" price (what you can sell your shares for) and the best ""ask"" price (what you can buy those shares for) because that's what is required.  That being said, there are many other market makers on the same stock whose bid prices are lower and ask prices are higher.  Many times there will be a big clump of market makers all at the same bid/ask, or within fractions of a cent of each other, all competing for business.  Trading computers are taught to seek out the best prices and the fastest trade fills they can. The point to this very simplistic lesson is that the market makers set the prices that shares trade at.  They adjust those prices based (among other factors) on how much buying and selling volume they're seeing.  If they see a wave of sell orders coming into the system then they'll start marking down their bid prices.  This keeps them from paying too much for shares they're going to have to find a buyer for eventually, and it can sometimes slow down the pace of selling as investors and automated systems notice the price decline and decide to wait to sell.  Conversely, if market makers see a wave of buy orders coming into the system, they'll start marking their ask prices up to maximize their gains, since they're selling you shares they bought from someone else, presumably at a lower price.  But they typically adjust their prices up or down before they actually fill trades.  (sneaky, eh?) Depending on how much volume there is on the shares of the company you're selling, and depending on whether there are more buyers than sellers at the moment, your share sell order may be filled at market by a market maker with no real consequence to the share's price. If the block is large enough then it's possible it will not all sell to one market maker, or it might not all happen in one transaction or even all at the same price. This is a pretty complex subject, as you can see, and I've cut a LOT of corners and oversimplified much to keep it comprehensible.  But the short answer to your question is -- it depends. Hope this helps. Good luck!" Options can have a negligible time premium. For American1 calls the time premium is never negative. If it had a negative premium it would be profitable to exercise it immediately. A deep in the money call has a delta of exactly one. That is, it's price movements completely mirror the price movements of the underlying stock. That means an option seller can buy stock and completely hedge his short option position. The seller of the option may be in an position to buy with very little margin and take your money and invest it. For example, consider a stock trading at $7.50, with its January 2014   $4 call option trading at $3.50. For one option, representing 100 shares, a trader could take your 350 dollars and invest it, and only use a small portion of the money to buy the stock on margin. Market-makers can typically borrow money at very low interest rates. If you have high borrowing costs, or are unable to buy on margin, then buying deep in the money calls can be a good strategy. Long story short, option sellers are making money off selling these deep in the money calls even with almost zero time premium. So, in general, there's no way to make money by buying them. 1. An American call is a call that can be exercised at any time up to and including its expiration date.