Do marketmakers always quote a bid and ask simultaneously
"Market makers (shortened MM) in an exchange are generally required to list both a bid and ask price to allow both buyers and sellers to trade and keep the market moving.  However, a more general idea of a MM may includes companies off an exchange (say large banks acting as broker/dealers in an over-the-counter market) are not required to give a simultaneous bid/ask, but often will on request.  So, it might depend on where you are getting this data but likely the bid/ask was quoted simultaneously. An exchange, like the NASDAQ for instance, may have multiple MMs for a given market.  The ""market"" spread will be from the highest bid to the lowest ask over all the MMs.  The highest bid and lowest ask may come from different MMs and any particular MM often will have a larger spread. The size of the spread gives a rough idea of how much a MM is trying to make off of a ""round trip"" trade (buying than immediately selling to someone else or selling than immediately buying from someone else).  Of course, immediate round-trip trades are not always possible and there are many other complications.  However, half the spread is a rough indicator of how much they hope to make off of a single trade." Yes, but also note each exchange have rules that states various conditions when the market maker can enlarge the bid-ask (e.g. for situations such as freely falling markets, etc.) and when the market makers need to give a normal bid-ask. In normal markets, the bid-asks are usually within exchange dictated bounds.  MM's price spread can be larger than bid-ask spread only when there are multiple market makers and different market makers are providing different bid-asks. As long as the MM under question gives bid and ask within exchange's rules, it can be fine. These are usually rare situations. One advice: please carefully check the time-stamps. I have seen many occasions when tick data time-stamps between different vendors are mismatched in databases whereas in real life it isn't.  MM's profits not just from spreads, but also from short term mean-reversion (fading). If a large order comes in suddenly, the MM increases the prices in one direction, takes the opposite side, and once the order is done, the prices comes down and the MM off-loads his imbalance at lower prices, etc.
Actually the insertion part is interesting because they actually aren't middlemen just faster buyer's and sellers on the open market. They just buy what one person is selling and sell it to someone else who is at the same time looking to buy. So I guess the issue is the 'same time' isn't the same for all parties concerned. On the other hand both buyer and seller can set limits on the bounds of the price and only transact when someone meets their terms. If you are willing to accept 'whatever the market will bear' then it seems like you should be OK with getting it. "I am not familiar with this broker, but I believe this is what is going on: When entering combination orders (in this case the purchase of stocks and the writing of a call), it does not make sense to set a limit price on the two ""legs"" of the order separately. In that case it may be possible that one order gets executed, but the other not, for example. Instead you can specify the total amount you are willing to pay (net debit) or receive (net credit) per item. For this particular choice of a ""buy and write"" strategy, a net credit does not make sense as JoeTaxpayer has explained. Hence if you would choose this option, the order would never get executed. For some combinations of options it does make sense however. It is perhaps also good to see where the max gain numbers come from. In the first case, the gain would be maximal if the stock rises to the strike of the call or higher. In that case you would be payed out $2,50 * 100 = $250, but you have paid $1,41*100 for the combination, hence this leaves a profit of $109 (disregarding transaction fees). In the other case you would have been paid $1,41 for the position. Hence in that case the total profit would be ($1,41+$2,50)*100 = $391. But as said, such an order would not be executed. By the way, note that in your screenshot the bid is at 0, so writing a call would not earn you anything at all." Not that I am aware. There are times that an option is available, but none have traded yet, and it takes a request to get a bid/ask, or you can make an offer and see if it's accepted. But the option chain itself has to be open. "EVERYONE buys at the ask price and sells at the bid price (no matter who you are). There are a few important things you need to understand. Example: EVE bid: 16.00 EVE ask: 16.25 So if your selling EVE at ""market price"" you are entering an ask equal to the highest bid ($16.00). If you buy EVE at ""market price"" you are entering a bid equal to the lowest ask price ($16.25). Its key to understand this rule: ""An order executes ONLY when both bid and ask meet. (bid = ask)."" So a market maker puts in a bid when he wants to buy but the trade only executes when an ASK price meets his BID price. When you see a quote for a stock it is the price of the last trade. So it is possible to have a quote higher or lower then both the bid and the ask." I'm not exactly sure, but it may be due to liquidity preference.  SPY has a much higher volume (30d average of roughly 70m vs. 3.3m, 1.9m for IVV, VOO respectively), and similarly has a narrow bid ask spread of about 0.01 compared to 0.02 for the other two.  I could be wrong, but I'm going to leave this post up and look in to it later, I'm curious too. The difference is very consistent though, so it may be something in their methodology. The situation you're proposing is an over-simplification that wouldn't occur in practice. Orders occur in a sequence over time. Time is an important part of the order matching process. Orders are not processed in parallel; otherwise, the problem of fairness, already heavily regulated, would become even more complex. First, crossed and locked markets are forbidden by regulators.  Crossed orders are where one exchange has a higher bid than another's ask, or a lower ask than another's bid.  A locked market is where a bid on one exchange is equal to the ask on another.  HFTs would be able to make these markets because of the gap between exchange fees. Since these are forbidden, and handling orders in parallel would ensure that a crossed or locked market would occur, orders are serialized (queued up), processed in order of price-time priority. So, the first to cross the market will be filled with the best oldest opposing order. Regulators believe crossed or locked markets are unfair.  They would however eliminate the bid ask spread for many large securities thus the bid-ask cost to the holder. "For every buyer there is a seller. That rule refers to actual (historical) trades. It doesn't apply to ""wannabees."" Suppose there are buyers for 2,000 shares and sellers for only 1,000 at a given price, P. Some of those buyers will raise their ""bid"" (the indication of the price they are willing to pay) above P so that the sellers of the 1000 shares will fill their orders first  (""sold to the highest bidder""). The ones that don't do this will (probably) not get their orders filled. Suppose there are more sellers than buyers. Then some sellers will lower their ""offer"" price to attract buyers (and some sellers probably won't). At a low enough price, there will likely be a ""match"" between the total number of shares on sale, and shares on purchase orders." Many of the Bitcoin exchanges mimic stock exchanges, though they're much more rudimentary offering only simple buy/sell/cancel orders.  It's fairly normal for retail stock brokerage accounts to allow other sorts of more complex orders, where once a certain criteria is met, (the price falls below some $ threshold, or has a movement greater than some %) then your order is executed.  The space between the current buy order and the current sell order is the bid/ask spread, it's not really about timing.  Person X will buy at $100, person Y will sell at $102.  If both had a price set at $101, they would just transact.  Both parties think they can do a little bit better than the current offer.  The width of the bid/ask spread is not universal by any means.  The current highest buy order and the current lowest sell order, are both the current price.  The current quoted market price is generally the price of the last transaction, whether it's buy or sell. I would say it's a bit more complicated than that. Do you understand what a market maker does?  An ECN (electronic communication network) is a virtual exchange that works with market makers. Using a rebate structure that works by paying for orders adding liquidity and charges a fee for removing liquidity. So liquidity is created by encouraging what are essentially limit orders, orders that are outside of the current market price and therefore not immediately executable. These orders stay in the book and are filled when the price of the security moves and triggers them.  So direct answer is NYSE ARCA is where market makers do their jobs. These market makers can be floor traders or algorithmic. When you send an order through your brokerage, your broker has a number of options. Your order can be sent directly to an ECN/exchange like NYSE ARCA, sent to a market making firm like KCG Americas (formerly Knight Capital), or internalized. Internalization is when the broker uses an in house service to execute your trade. Brokerages must disclose what they do with orders. For example etrade's. https://content.etrade.com/etrade/powerpage/pdf/OrderRouting11AC6.pdf This is a good graphic showing what happens in general along with the names of some common liquidity providers. http://www.businessweek.com/articles/2012-12-20/how-your-buy-order-gets-filled What you have to remember is that Options are derivatives of another asset like stocks for example.  The price of the Option is derived from the price of the underlying. If the underlying is a stock for example, as the price of the stock moves up and down during the trading day, so will the Market Maker's fair value for the Option.  As Options are usually less liquid than the underlying stock, Market Makers are usually more active in 'Providing a Market' with Options. Thus if you place a limit order half way between the current Bid and Ask and the underlying stock price moves towards your limit order, the Market Maker will do their job and 'Provide a Market' at that price, thus executing your order. "Yes, this is common and in some cases may be required.  They may use it for marketing at some level, but they also use it for risk management in deciding, for example, how much margin to offer and whether to approve access to ""riskier"" products like stock options." When you place a bid between the bid/ask spread, that means you are raising the bid (or lowering the ask, if you are selling). The NBBO (national best bid and offer) is now changed because of your action, and yes, certain kinds of orders may be set to react to that (a higher bid or lower ask triggering them), also many algorithms (that haven't already queued an order simply waiting for a trigger, like in a stop limit) read the bid and ask and are programmed to then place an order at that point. "At least for liquid markets, the downside of being a market maker is what we call ""negative selection"". Specifically, if you're both bid and offered in a market, trying to collect your spread, then as the market goes up, you'll tend to sell the whole way up, and vice versa. So if you're not smart about it, you can end up losing a lot of money.   Being a good market maker, then, involves either being able to smarter about when to be aggressively bid and offered and when to pull back, or being able to hedge them quickly before they really hurt you. The first probably would require more sophisticated algorithms, while the second requires good speed and execution strategies." Sounds to me like you're describing just how it should work.  Ask is at 30, Bid is at 20; you offer a new bid at 25.  Either: Depending on liquidity, one or the other may be more likely. This Investorplace article on the subject describes what you're seeing, and recommends the strategy you're describing precisely. Instead of a market order, take advantage of the fact that the options world truly is a marketplace — one where you can possibly get a better price just by asking. How does that work? If you use a limit order (instead of a market order) when opening a position, you can tell your broker how much you are willing to pay to enter a trade. For example, if you enter a limit price of $1.15, you can see whether the market-maker will bite. You will be surprised at how many times you will get your price (i.e., $1.15) instead of the ask price of $1.30. If your order at $1.15 is not filled after a few minutes, you can modify your order and pay the ask price by entering a market order or limit order at the ask price (that is, you can tell your broker to pay no more than $1.30). If you are the only one who puts in a large market buy order, then it would definitely push the price up. How much up would depend on how many would be willing to sell at what price point. It would also be possible that your trade will not get executed as there are no sellers. The same would be true if you put in a large sell order, with no buyers. The price would go down or trade not get executed as there aren't enough buyers.